The sneaker features large flat laces and an oversized rubber sole. Passing a swarm of lenses, Vivienne pivots every interviewer's question to her accessory: "I've got some brilliant jewelry here," she says to CNN, pointing to the soldier's photo now pinned to her long pink silk coat. She made A-line pinafores and popped turtlenecks under them, and came up with jazzy jersey colors in minimal...