An untitled work by Martin Kippenbereger, bottom, is reflected in a work by Michelangelo Pistoletto titled "Metrocubo d'infinito" (Cubic Metre of Infinity), which sits in front of a work titled "Concetto Spaziale, " by Lucio Fontana, top, during a press preview at Christies Auction House, Oct. 5, 2012, in London. (Dan Kitwood/Getty Images)