Consciousness of the Queen and her splendidly unchanging stately style—those edge-to-edge tweed coats; her unmissable bright-pastel palette—is creeping into all sorts of places at the moment. On Erdem’s pinboard, she’s been sharing space with his research photographs of Upper East Side ladies, posing neatly on their upholstered sofas and armchairs, and Amish women, in their long, modestly cut dresses.