A film industry slang term. Used as a way to tell actors and crew to hurry up as natural daylight wanes. Since the sun's position and quality changes throughout the day, sunlit shoots can be challenging to match later in editing, so it's important to get scenes done efficiently. This phrase is often used jokingly indoors to spur on the film crew.
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.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"