In 1838, Louis Daguerre snapped a photo of a Parisian street, empty but for a shoeshine boy and his client. Now that some sleuths have zeroed in on the location, the city is marking it with a plaque.

Brands from Jenni Kayne to Fabletics have flooded into the category in recent months, but breaking through requires an obsessive attention to fit and a distinctive point of view. For her brand’s ...