This is the action of liking something on facebook and then immediately unliking it so that the person gets a notification that you liked their post, but when they check, they realize that you haven't
I saw that you psych liked my post. War has now been declared.
A "like psyche" is when you "like" something on Facebook, giving it a thumbs up, and then immediately "unlike" it. The person will receive a notification that you "like" their post, only to find the thumbs up is gone. This prank is most effective if accompanied by a comment about the sweet "like psyche" you just pulled.
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.