When Kate Middleton stepped out in a blush pink Elie Saab gown at the royal wedding of Crown Prince Hussein of Jordan and Rajwa Al Saif in Amman, she did not simply attend a wedding. She delivered a lesson in how to dress as a royal guest, one that left fashion watchers and royal observers taking notes. The look was calm, considered, and deeply intentional. It was celebrity style filtered through the specific grammar of royal fashion, and it worked in every possible way.