Definition: The slang or profane term you're referring to is "snapshot". Let's explore why this term is so fun and how it can be used humorously.
Snapshot: When a person or an object looks at your screen without looking at the content, they are essentially taking a snapshot of themselves with their phone. This phrase comes from a line in the movie "Shrek" where Fiona asks her friend about the film "The Lion King", and her friend responds by taking a screenshot of the screen. Example sentence: "You see, I just took a snapshot of you while you were playing games on your phone!"