Definitely an art piece, there's not enough shit and piss on every surface to be a real bathroom. Unless it's some sort of rare Jackson Pollock scupture piece making fun of Andy Worhol, in which case, there isn't enough shit, piss, cum, and/or blood.
Admittedly, I'm a little biased. I traveled a lot up and down the east coast as a pro skater when I was younger, lot of questionable rest stops and roach motels. I also worked as a plumber for years. Lot of multimillion dollar homes, yacht clubs, small businesses. Let me tell you though, lifestyles of the rich and famous does not cover how much the rich like to blow up a yacht club toilet and leave it for the help to deal with...
Worst by far though? There's a Lowes Theatre near me that routinely has enough shit on the tiled walls that it looks like bad grout work.