MILAN — There is more than one way of spinning spring’s short and sultry looks. Miuccia Prada, for example, who startled the fashion world with her Prada glamazons for fall, moved away from that overt sexiness for spring. She placed her own stamp on miniskirts, giving them a young, slightly Sixties dimension — along with a touch of the junior jet set. Here, her mix of the sensual and sporty for Prada: a revealing tank suit and wrap skirt. For more on the season, see pages 4 and 5.