Artistic fetish

Piper's theory of art as fetish is an interesting one. Art is indeed treated absolutely uniquely, given special views and qualities simply because it is art. We attribute special qualities (see aesthetic properties among other things) to it, and elevate it above the mundane simply because it is art. What does making it special add to it? Why does it need to be special, or seen as 'above' normal things? Is this simply to distinguish it from what can, in many cases, be identical(see the urinals stamped with names, or the paintings of brillo boxes, other such paraphernalia)?