Pop jokester Jeff Koons is sitting pretty on top of the art-world market — his Hanging Heart, a giant version of a cheap jewelry pendant, fetched over $22 million last fall, setting a record for a living artist — and now three of his works are perched atop the Metropolitan Museum of Art. The artist's enormous replicas of a chocolate heart wrapped in red cellophane, a poorly colored-in picture of Piglet from a Winnie the Pooh coloring book, and a golden balloon-animal dog will spend their summer on the museum's roof deck. The New York Times called the works "mischievously meaningful," and concluded, "Mr. Koons' sculptures remain intellectually and sensuously exciting objects."