The origin of the term is that thing a girl does when she's plucking her eyebrows where she switches back and forth trying to get things even, but accidentally takes too much off EVERY time until there is no eyebrow left.
Despite the origin, this term applies to haircuts, makeup, and even external things the girl does.
Jer: Your hair looks fine woman, stop eyebrowing!
Rosey: No wait, I'm almost done, my hair is uneven!
Jer: You are such an eyebrower!
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.