What is art?
Art, in my opinion, at it's very base is any route from point A to point B that is not the most direct route. These, obviously, aren't always physical points. With movement art, such as dance, it is all of the flourishes and stylization that happens between the starting and the end point that make it art. One could just walk across the stage, but people find meaning and enjoyment in the leaps, the arm movements, the spins, and the just over exaggerated movement from point A to point B.
In visual arts, the same idea applies. Not taking the most direct path to make your point. Sure one could have a sign saying "War is bad", and while it make the point, but showing photographs of the effects of war one makes a more powerful statement, while at the same time blurring their point. it is though deciphering the meaning that art gins strength. However, all things in moderation. When the meaning becomes so blurred that it becomes impossible to find, or everyone takes their own different meaning from it, it loses strength. It is a fine line.
But even those pieces, who's meaning is not easily accessible, count as art, because they are not there for the utilitarian A to be B, but rather to stimulate the mind and heart.