Same way a postmodern book (Catch-22, Slaughter-House Five), a postmodern movie (Blade Runner, Taxi Driver), or a postmodern building (Portland Building, One Detroit Center) works. Playing with the very concept of what classifies a work of art while still being a successful work in and of itself.
This is why we need to exterminate the art students. Art with a purpose is the only art that fucking matters.