When you're lured into someone's house under false presences, only for your host to 'let the shutters down'. Usually under the guise of a sporting event
I’ll put the shutters down on Saturday if we go back to mine to watch the rest of the games
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.