That's because POP is all about everything that a major fragrance usually isn't. There's no come-hither ad campaign, no wear-this-to-make-a-lover-swoon messaging. (The print ad, a simple close-up of the four faces, "was about letting the girls be themselves and not airbrushing them. Letting them have eyebrows and roots and the whole shebang," McCartney says.)

— Read more at Stella McCartney's New Scent Breaks All the Major Fragrance Rules at Elle.