SYDNEY—About 5,200 naked people embraced each other on the steps of Sydney's iconic Opera House on Monday for a photo shoot by Spencer Tunick. Tunick, who is known for his nude group photos in public spaces, posed participants for more than an hour in a variety of positions. "It was difficult to get the straight participants to embrace the gay participants and vice versa," Tunick said. "So I was very happy that that last set up finally got done and everyone came together (in a) united, friendly kiss, a loving kiss in front of this great structure."