I know, this looks weird.

But it looks REALLY comfortable!
look at the guy, probably having the sleep of his life.

It is designed to fit snugly around your neck so that your head will not tip very much. So, when you let your chin fall forward or to the side, your head won't tip but your double-chins might bulge out.

Don't worry - the cabin lights will most likely be out anyway, and other passengers will probably be more interested in watching their movies than a double chin.