Three types of photograph

I'm not sure that I've not ruminated along these lines in the past but here goes...

On the tram to work this morning I was thinking how best to describe the photography in one of the photobooks I own, with a view to writing a review. That led to the notion of three types of photograph:

Photograph as object - the fine print, fine art end of the spectrum. A photograph where seeing the physical print is as much a part of the experience as the content.
Photograph as subject - such that it is what stood in front of the camera is the key. It is all about capturing an image of something physical.
Photograph as idea - the notion of metaphor or representation. The means of presentation matters less than the response of the viewer.

I wouldn't say that these are pure concepts or even categories, more axes. Photographs may be mixtures of the types. I'm unsure whether means of presentation might influence one's idea of which a given picture may be (I can think of a few fine art prints that move from object to subject when seen in books rather than as a full-size print).

And so it followed, in my thought train, that message and medium become somewhat bound. How a photographer wants the work to be considered influences means of presentation (print, book, screen etc) and a corollary being that the means of presentation will affect the viewers response.