This is a puzzling question. What makes a particular photograph “art”.

The technical quality of the photo? (thinking about physical (analogue) techniques vs. digital effects)

The content / context relationship?

The person taking the photo?

The context of which the photo is displayed?

A unique vantage point?

A conceptual quality?

Can the photograph (object) just be that which is simply a beautiful thing itself to view – or does the subject “in” the photo matter too much ?

That which provokes an emotional response – to me, to you and me, to a bunch of others ?

That which makes the ordinary seem extraordinary?

That which allows us to see the thing that normally is missed?

 

See also Michael Wesely: Open Shutter at The Museum of Modern Art

and more about Wesely here http://www.wesely.org