Person 1: Brb <after some waiting>
Person 2: ihtgttbr bbttyftoiwbb
<more waiting>
Person 2: back
Person 2: you aren't back yet? omg, hurry up!
Person 2: i told you...
Person 1: back
Person 2: god, finally!
Person 1: why'd you say i told you?
Person 2: i said ihtgttbr bbttyftoiwbb!!! douche
Person 1: i don't get it...
Person 2: URBANDICTIONARY.COM, they'll tell ya...now go talk to someone that cares.
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.