I have a coworker who is friends with a supervisor-level employee. (This isn’t an isolated event, obviously.) The supervisor-level employee is not above my coworker or me. Completely outside of our power structure.
Anyway, this supervisor-level employee stops by my coworker’s desk on occasion and about 98% of the time it is for personal reasons - shared hobby, schedule get-togethers, or whatever. The supervisor always, 100% of the time, interrupts whatever conversation my coworker is having. If my coworker is in the middle of an informal business meeting at her desk, the supervisor interrupts. Even if there are three or more people involved in this business meeting, the supervisor interrupts.
Sometimes the supervisor is “polite” and only interrupts for a quick second. Sometimes the supervisor’s interruption will devolve into five minutes of random chit-chat that is completely disruptive. Every once in a while the supervisor will apologize. (As one of my high school math teachers once said, “Don’t say you are sorry if you are going to do it again.”) However, I’ve never noticed the supervisor simply walk on by my coworker’s cube when my coworker is busy.
I’m not sure if this is simply a poor personal trait or if it is a power thing. More than likely it is a subconscious mix. Whatever the case, it is annoying to no end.