If you haven't got a mirror on hand, you use whatever reflective surface is available to check your makeup. And if it's a gigantic knife blade, so be it.
Emma Roberts wields perfect lipstick and a pointed blade in the new teaser for Scream Queens. We don't see much else, but really, do we need to?
In the first teaser released for the show, a bubbly blonde sorority type blows a bubble that gets popped by a knife and a wash of blood. In the second one, called "Chanel Bubblegum" Roberts exits a sorority house and blows a bubble that turns into a freaky demon face. Between that and the new teaser, it seems like Roberts is preparing to reprise her bad-girl vibes from American Horror Story.