Last night's Rx Art Party, held at Milk Gallery, was hosted by Jack McCollough and Lazaro Hernandez, the magnificently talented and dreamy design duo behind Proenza Schouler. The honoree of this charity event was Jeff Koons, who will be placing his signature elephants, topiary dogs and inflatable rabbits at the Advocate Hope Children's Hospital in Chicago to promote a cheerful atmosphere in an otherwise scary place for kids.