The fabric literally floats. The Daily Mail has an interview with Sandy Powell, the creator of Lily James’ ridiculously gorgeous Cinderella ballgown. She revealed some of the secrets behind the iconic dress and they’re fascinating: 1. There are eight versions of the gown, and they’re all different. “One was 2 inches shorter and a couple were 4 inches for the times when Lily had to run; another had holes cut …