Mixed in among the cheery tropical prints Diane von Furstenberg showed at her new Meatpacking District digs was some heavy metal. A snakeskin pattern slithered across a metallic taffeta frock, exposed zippers became decorative elements on a minidress, and studs toughened up a skirt. Tunics, halters, and A-line silhouettes took the place of the designer's signature wraps.