Visiting the world of Meret Oppenheim is a little like confronting Object, her famed fur teacup—the viewer is tempted to imagine what’s underneath. It’s just an ordinary teacup, isn’t it—but is it?  Such layers and layers of surprises await. The current retrospective at MOMA has unearthed through nearly 200 paintings, sculptures, assemblages, reliefs, jewelry designs, works on paper, and collages to reflect a marvelously fluid mind.