“Perfumers have signatures,” Mrs. Grojsman said. “You can pick up a fragrance and know who the perfumer is by the way certain ingredients are put together. I’m known for floral accords, bottoms and cleavage.” Noses talk that way. Translation: the bottom note is the scent on the skin several hours after application. There is, however, no bottom without a top — a note that lasts a couple of minutes after perfume is put on — and a middle. Without this layering, heaven forbid, a scent could turn out to be what Mrs. Grojsman called “a bottomless pit of infinity or nondescript.” Cleavage is the “sensual” part of the fragrance.