At the opening of the Whitney Museum of American Art in the Meatpacking District on May 1, Keith Haring art was in evidence. Yes, of course, in the museum’s exhibition, “America Is Hard To See,” but also on people waiting in line to get in. As the photographer was getting a shot of one Whitney-goer’s Haring tattoo, another guy on line kicked up his sneaker heels to show pink babies, one of the artist’s signature motifs.