Back for Tea: Written on the in/out board at work when you are at meeting to let the maker know that even though you are out of office they should still make you a cup of tea/coffee at tea break
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.