As a very pragmatic sort of bloke, if you ask a question like "Is this art?", then in order to answer it you have to define precisely what you mean by 'art'.
Having done that, you can then try to match the qualities you see in the image with your definition of art, and then claim that according to this particular definition of art, this particular photo does or does not meet the requirements to be deemed as 'art'.
Of course, others will no doubt disagree with your matching process, and if they don't disagree with this, then they are likely to disagree with the definition, so such questions are unanswerable in any absolute sense.
I get the impression the photographer who took the image in question was trying to create a pensive, floating, ambiguous mood of mystery, which is the 'artistic' paradigm.