I've been musing recently on what a subject of a photographic image means. Mostly, I'm posting to read the responses, so if you have any opinions, please add your comments. (In other languages is fine, I'll translated using babelfish.)

Traditionally, a subject is something like a person, animal or flower. We are told it should be properly lit and we are told of the rule of thirds.

I would like to ask about a different type of subject. Can't the subject be an abstract idea, such as "periodicity" (a repeating pattern or rotational symmetry)? Can't the subject be a geometrical idea suggested by the image? This is not the same as an abstract image, in which the color and form is not representative of an actual (real) image (such as with a Jackson Pollack painting). It also seems different than so-called "geometric abstraction", as in a Kandinsky painting. In both cases, the image is not representational. I mean a photographic image of a real object, such as a row of windows which seems to go off to infinity in a repetitive pattern, like this photo of Jake's or this: