From left: director Luca Guadagnino with Marthe Keller, Julianne Moore and Pierpaolo Piccioli in Cannes. AP
From left: director Luca Guadagnino with Marthe Keller, Julianne Moore and Pierpaolo Piccioli in Cannes. AP

Why filmmaker Luca Guadagnino makes the most fashionable films around