Her gaze drifts somewhere past the horizon, chin lifted, spine straight, utterly sure of herself. The fan in her hand does something subtle, something almost theatrical. For centuries, people have puzzled over what that small gesture actually meant. Stories abound about a secret code, one where a flick of the wrist or a particular angle supposedly carried a hidden message between lovers, rivals, or strangers across a crowded room. This summer, that gesture suddenly feels familiar again. As…