Photograph, ImageObject, photo, image, thumbnail, thumbnailUrl etc.

Hello,

I would like to understand better modeling of Photograph and ImageObject
in schema.org. I also hope to make at some point simple diagram for it,
something similar to the rough sketch included in
https://twitter.com/elfpavlik/status/574193664974520320


## ImageObject
http://schema.org/ImageObject
An image file.

it stays in domainIncludes of

-- thumbnail --> ImageObject
Thumbnail image for an image or video.

via MediaObject it stays in rageIndludes of

-- contentUrl --> URL
Actual bytes of the media object, for example the image file or video file.

-- contentSize --> Text
File size in (mega/kilo) bytes.

-- encodingFormat --> Text

-- height --> Distance | QuantitativeValue
The height of the item

-- width --> Distance | QuantitativeValue
The width of the item.

via Thing it stays in domainIncludes of
-- image --> ImageObject

I get impression that this focuses on describing the 'actual file' with
contentSize, encodingFormat, height, width etc.


## Photograph
http://schema.org/Photograph
A photograph.

!!! no examples !!!

via CreativeWork it stays in domainIncludes of

-- associatedMedia | encoding --> MediaObject
(synonyms) A media object that encodes this CreativeWork.

-- thumbnailUrl --> URL
A thumbnail image relevant to the Thing.

-- review --> Review
A review of the item.

-- discussionUrl --> URL
A link to the page containing the comments of the CreativeWork.

via Thing it stays in domainIncludes of
-- image --> ImageObject


I get impression that this serves in a way as 'Social Artifact' which
one reviews, comments on etc.


QUESTIONS

1. Since both ImageObject and Photograph subclass CreativeWork which
'provides' social properties (review, discussionUrl). As currently
Photograph doesn't 'include' any new properties, one could consider
ImageObject subClassOf Photograph. At least ImageObject stays within
domainIncludes of all the properties that Photograph does + more.

2. thumbnail & thumbnailUrl - intentional or accidental?

CreativeWork (parent class of both) uses
-- thumbnailUrl --> URL
A thumbnail image relevant to the Thing.

ImageObject additionally stays in domainIncludes of
-- thumbnail --> ImageObject
Thumbnail image for an image or video.

I must also admit not understanding rangeIncludes URL! Why not just
rangeIncludes Thing? (in JSON-LD "@type": "@id" ?)

http://schema.org/URL
Data type: URL.

http://schema.org/Thing
The most generic type of item.

3. image & photo - intentional or accidental? Why does Place need
specialization of image property?

Place stays in domainIncludes of

-- photo --> Photograph | ImageObject
A photograph of this place.

and via Thing it stays in domainIncludes of

-- image --> URL | ImageObject
An image of the item. This can be a URL or a fully described ImageObject.

schema.rdfa also includes

schema:photo rdfs:subPropertyOf schema:image

4. PhotographAction results in?

http://schema.org/PhotographAction

IMO has incorrect example
"John took a photo of Steve."

{
  "@context": "http://schema.org",
  "@type": "PhotographAction",
  "agent": {
    "@type": "Person",
    "name": "John"
  },
  "object": {
    "@type": "ImageObject",
    "url": "http://john.com/steve.jpg"
  }
}

I would use

{
  "@context": "http://schema.org",
  "@type": "PhotographAction",
  "agent": {
    "@type": "Person",
    "name": "John"
  },
  "object": {
    "@type": "Person",
    "name": "Steve"
  }
  "result": {
    "@type": "ImageObject",
    "url": "http://john.com/steve.jpg"
  }
}

Any help with clarifying nuances of Photograph / ImageObject much
appreciated!

Cheers