2009.128 . Tray Sculptor
The cafeteria has gone "trayless" to save water and energy, leaving the trays to artists like this one. That's dirt and a flower stuck to the tilted pile of trays. A nice metaphor for turning back to the environment (and a metaphor that probably didn't need explaining, but I like explaining things anyway sometimes).
Back when trays were in use, students would put some of their food directly on the trays to avoid using another plate. A biology teacher explained that the trays never really got very clean in the washing process because of the finely textured grooves in their construction, so they were an excellent place for bacteria to flourish ... yet another good reason for the move to a trayless caf.