American Apparel must have recently discovered that nobody was talking about their garage-porn styled photos anymore, so they switched to pencil sketches instead. With pencil sketches they can go even further with their tantalizing tease-images and have the model remove her panties while putting on her best come-hither look. And they're not just any old pencil sketches, these look like the work of Boris Vallejo the master painter of the fantasy and erotica genres whose art hung in every adolescent males room back in the 70s. A match made in heaven, really, the only better one I can think of is the Lynx / Axe posters that used Boris Vallejo's art. The erotica-art is done by Boris Lopez, whose body of work concentrates on females pulling down their underwear.
See Boris Lopez for more panty-less illustrations.
*edit - I put Vallejo's name in the headline at first. Do'h.