diff --git a/scripts/paycheck.py b/scripts/paycheck.py
index 9689af4..9852ded 100755
--- a/scripts/paycheck.py
+++ b/scripts/paycheck.py
@@ -59,6 +59,8 @@
   check_opts.add_option('-c', '--check', action='store_true', default=False,
                         help=('force payload integrity check (e.g. before '
                               'applying)'))
+  check_opts.add_option('-D', '--describe', action='store_true', default=False,
+                        help='Print a friendly description of the payload.')
   check_opts.add_option('-r', '--report', metavar='FILE',
                         help="dump payload report (`-' for stdout)")
   check_opts.add_option('-t', '--type', metavar='TYPE', dest='assert_type',
@@ -175,6 +177,9 @@
       # Initialize payload.
       payload.Init()
 
+      if options.describe:
+        payload.Describe()
+
       # Perform payload integrity checks.
       if options.check:
         report_file = None
diff --git a/scripts/update_payload/payload.py b/scripts/update_payload/payload.py
index fefc7e4..1796f51 100644
--- a/scripts/update_payload/payload.py
+++ b/scripts/update_payload/payload.py
@@ -154,6 +154,30 @@
 
     self.is_init = True
 
+  def Describe(self):
+
+    def _DescribeImageInfo(description, image_info):
+      def _DisplayIndentedValue(name, value):
+        print '  {:<14} {}'.format(name+':', value)
+
+      print '%s:' % description
+      _DisplayIndentedValue('Channel', image_info.channel)
+      _DisplayIndentedValue('Board', image_info.board)
+      _DisplayIndentedValue('Version', image_info.version)
+      _DisplayIndentedValue('Key', image_info.key)
+
+      if (image_info.build_channel != image_info.channel):
+        _DisplayIndentedValue('Build channel', image_info.build_channel)
+
+      if (image_info.build_version != image_info.version):
+        _DisplayIndentedValue('Build version', image_info.build_version)
+
+    if self.manifest.HasField('old_image_info'):
+      _DescribeImageInfo('Old Image', self.manifest.old_image_info)
+
+    if self.manifest.HasField('new_image_info'):
+      _DescribeImageInfo('New Image', self.manifest.new_image_info)
+
   def _AssertInit(self):
     """Raises an exception if the object was not initialized."""
     if not self.is_init:
diff --git a/scripts/update_payload/update_metadata_pb2.py b/scripts/update_payload/update_metadata_pb2.py
index 92a7506..71803f5 100644
--- a/scripts/update_payload/update_metadata_pb2.py
+++ b/scripts/update_payload/update_metadata_pb2.py
@@ -10,7 +10,7 @@
 DESCRIPTOR = descriptor.FileDescriptor(
   name='update_metadata.proto',
   package='chromeos_update_engine',
-  serialized_pb='\n\x15update_metadata.proto\x12\x16\x63hromeos_update_engine\"1\n\x06\x45xtent\x12\x13\n\x0bstart_block\x18\x01 \x01(\x04\x12\x12\n\nnum_blocks\x18\x02 \x01(\x04\"z\n\nSignatures\x12@\n\nsignatures\x18\x01 \x03(\x0b\x32,.chromeos_update_engine.Signatures.Signature\x1a*\n\tSignature\x12\x0f\n\x07version\x18\x01 \x01(\r\x12\x0c\n\x04\x64\x61ta\x18\x02 \x01(\x0c\"+\n\rPartitionInfo\x12\x0c\n\x04size\x18\x01 \x01(\x04\x12\x0c\n\x04hash\x18\x02 \x01(\x0c\"\x99\x07\n\x14\x44\x65ltaArchiveManifest\x12Y\n\x12install_operations\x18\x01 \x03(\x0b\x32=.chromeos_update_engine.DeltaArchiveManifest.InstallOperation\x12`\n\x19kernel_install_operations\x18\x02 \x03(\x0b\x32=.chromeos_update_engine.DeltaArchiveManifest.InstallOperation\x12\x18\n\nblock_size\x18\x03 \x01(\r:\x04\x34\x30\x39\x36\x12\x19\n\x11signatures_offset\x18\x04 \x01(\x04\x12\x17\n\x0fsignatures_size\x18\x05 \x01(\x04\x12>\n\x0fold_kernel_info\x18\x06 \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x12>\n\x0fnew_kernel_info\x18\x07 \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x12>\n\x0fold_rootfs_info\x18\x08 \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x12>\n\x0fnew_rootfs_info\x18\t \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x1a\xf5\x02\n\x10InstallOperation\x12P\n\x04type\x18\x01 \x02(\x0e\x32\x42.chromeos_update_engine.DeltaArchiveManifest.InstallOperation.Type\x12\x13\n\x0b\x64\x61ta_offset\x18\x02 \x01(\r\x12\x13\n\x0b\x64\x61ta_length\x18\x03 \x01(\r\x12\x33\n\x0bsrc_extents\x18\x04 \x03(\x0b\x32\x1e.chromeos_update_engine.Extent\x12\x12\n\nsrc_length\x18\x05 \x01(\x04\x12\x33\n\x0b\x64st_extents\x18\x06 \x03(\x0b\x32\x1e.chromeos_update_engine.Extent\x12\x12\n\ndst_length\x18\x07 \x01(\x04\x12\x18\n\x10\x64\x61ta_sha256_hash\x18\x08 \x01(\x0c\"9\n\x04Type\x12\x0b\n\x07REPLACE\x10\x00\x12\x0e\n\nREPLACE_BZ\x10\x01\x12\x08\n\x04MOVE\x10\x02\x12\n\n\x06\x42SDIFF\x10\x03')
+  serialized_pb='\n\x15update_metadata.proto\x12\x16\x63hromeos_update_engine\"1\n\x06\x45xtent\x12\x13\n\x0bstart_block\x18\x01 \x01(\x04\x12\x12\n\nnum_blocks\x18\x02 \x01(\x04\"z\n\nSignatures\x12@\n\nsignatures\x18\x01 \x03(\x0b\x32,.chromeos_update_engine.Signatures.Signature\x1a*\n\tSignature\x12\x0f\n\x07version\x18\x01 \x01(\r\x12\x0c\n\x04\x64\x61ta\x18\x02 \x01(\x0c\"+\n\rPartitionInfo\x12\x0c\n\x04size\x18\x01 \x01(\x04\x12\x0c\n\x04hash\x18\x02 \x01(\x0c\"w\n\tImageInfo\x12\r\n\x05\x62oard\x18\x01 \x01(\t\x12\x0b\n\x03key\x18\x02 \x01(\t\x12\x0f\n\x07\x63hannel\x18\x03 \x01(\t\x12\x0f\n\x07version\x18\x04 \x01(\t\x12\x15\n\rbuild_channel\x18\x05 \x01(\t\x12\x15\n\rbuild_version\x18\x06 \x01(\t\"\x8f\x08\n\x14\x44\x65ltaArchiveManifest\x12Y\n\x12install_operations\x18\x01 \x03(\x0b\x32=.chromeos_update_engine.DeltaArchiveManifest.InstallOperation\x12`\n\x19kernel_install_operations\x18\x02 \x03(\x0b\x32=.chromeos_update_engine.DeltaArchiveManifest.InstallOperation\x12\x18\n\nblock_size\x18\x03 \x01(\r:\x04\x34\x30\x39\x36\x12\x19\n\x11signatures_offset\x18\x04 \x01(\x04\x12\x17\n\x0fsignatures_size\x18\x05 \x01(\x04\x12>\n\x0fold_kernel_info\x18\x06 \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x12>\n\x0fnew_kernel_info\x18\x07 \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x12>\n\x0fold_rootfs_info\x18\x08 \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x12>\n\x0fnew_rootfs_info\x18\t \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x12\x39\n\x0eold_image_info\x18\n \x01(\x0b\x32!.chromeos_update_engine.ImageInfo\x12\x39\n\x0enew_image_info\x18\x0b \x01(\x0b\x32!.chromeos_update_engine.ImageInfo\x1a\xf5\x02\n\x10InstallOperation\x12P\n\x04type\x18\x01 \x02(\x0e\x32\x42.chromeos_update_engine.DeltaArchiveManifest.InstallOperation.Type\x12\x13\n\x0b\x64\x61ta_offset\x18\x02 \x01(\r\x12\x13\n\x0b\x64\x61ta_length\x18\x03 \x01(\r\x12\x33\n\x0bsrc_extents\x18\x04 \x03(\x0b\x32\x1e.chromeos_update_engine.Extent\x12\x12\n\nsrc_length\x18\x05 \x01(\x04\x12\x33\n\x0b\x64st_extents\x18\x06 \x03(\x0b\x32\x1e.chromeos_update_engine.Extent\x12\x12\n\ndst_length\x18\x07 \x01(\x04\x12\x18\n\x10\x64\x61ta_sha256_hash\x18\x08 \x01(\x0c\"9\n\x04Type\x12\x0b\n\x07REPLACE\x10\x00\x12\x0e\n\nREPLACE_BZ\x10\x01\x12\x08\n\x04MOVE\x10\x02\x12\n\n\x06\x42SDIFF\x10\x03')
 
 
 
@@ -39,8 +39,8 @@
   ],
   containing_type=None,
   options=None,
-  serialized_start=1134,
-  serialized_end=1191,
+  serialized_start=1373,
+  serialized_end=1430,
 )
 
 
@@ -176,6 +176,69 @@
 )
 
 
+_IMAGEINFO = descriptor.Descriptor(
+  name='ImageInfo',
+  full_name='chromeos_update_engine.ImageInfo',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    descriptor.FieldDescriptor(
+      name='board', full_name='chromeos_update_engine.ImageInfo.board', index=0,
+      number=1, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=unicode("", "utf-8"),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='key', full_name='chromeos_update_engine.ImageInfo.key', index=1,
+      number=2, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=unicode("", "utf-8"),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='channel', full_name='chromeos_update_engine.ImageInfo.channel', index=2,
+      number=3, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=unicode("", "utf-8"),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='version', full_name='chromeos_update_engine.ImageInfo.version', index=3,
+      number=4, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=unicode("", "utf-8"),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='build_channel', full_name='chromeos_update_engine.ImageInfo.build_channel', index=4,
+      number=5, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=unicode("", "utf-8"),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='build_version', full_name='chromeos_update_engine.ImageInfo.build_version', index=5,
+      number=6, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=unicode("", "utf-8"),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+  ],
+  extensions=[
+  ],
+  nested_types=[],
+  enum_types=[
+  ],
+  options=None,
+  is_extendable=False,
+  extension_ranges=[],
+  serialized_start=269,
+  serialized_end=388,
+)
+
+
 _DELTAARCHIVEMANIFEST_INSTALLOPERATION = descriptor.Descriptor(
   name='InstallOperation',
   full_name='chromeos_update_engine.DeltaArchiveManifest.InstallOperation',
@@ -249,8 +312,8 @@
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=818,
-  serialized_end=1191,
+  serialized_start=1057,
+  serialized_end=1430,
 )
 
 _DELTAARCHIVEMANIFEST = descriptor.Descriptor(
@@ -323,6 +386,20 @@
       message_type=None, enum_type=None, containing_type=None,
       is_extension=False, extension_scope=None,
       options=None),
+    descriptor.FieldDescriptor(
+      name='old_image_info', full_name='chromeos_update_engine.DeltaArchiveManifest.old_image_info', index=9,
+      number=10, type=11, cpp_type=10, label=1,
+      has_default_value=False, default_value=None,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='new_image_info', full_name='chromeos_update_engine.DeltaArchiveManifest.new_image_info', index=10,
+      number=11, type=11, cpp_type=10, label=1,
+      has_default_value=False, default_value=None,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
   ],
   extensions=[
   ],
@@ -332,8 +409,8 @@
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=270,
-  serialized_end=1191,
+  serialized_start=391,
+  serialized_end=1430,
 )
 
 
@@ -350,6 +427,8 @@
 _DELTAARCHIVEMANIFEST.fields_by_name['new_kernel_info'].message_type = _PARTITIONINFO
 _DELTAARCHIVEMANIFEST.fields_by_name['old_rootfs_info'].message_type = _PARTITIONINFO
 _DELTAARCHIVEMANIFEST.fields_by_name['new_rootfs_info'].message_type = _PARTITIONINFO
+_DELTAARCHIVEMANIFEST.fields_by_name['old_image_info'].message_type = _IMAGEINFO
+_DELTAARCHIVEMANIFEST.fields_by_name['new_image_info'].message_type = _IMAGEINFO
 
 class Extent(message.Message):
   __metaclass__ = reflection.GeneratedProtocolMessageType
@@ -375,6 +454,12 @@
   
   # @@protoc_insertion_point(class_scope:chromeos_update_engine.PartitionInfo)
 
+class ImageInfo(message.Message):
+  __metaclass__ = reflection.GeneratedProtocolMessageType
+  DESCRIPTOR = _IMAGEINFO
+  
+  # @@protoc_insertion_point(class_scope:chromeos_update_engine.ImageInfo)
+
 class DeltaArchiveManifest(message.Message):
   __metaclass__ = reflection.GeneratedProtocolMessageType