When I created the "affinity slider" back in 2011-2012 here weren't any models for what to call it because nobody else had such a thing. I've since floated the name "friend zoom" because that better describes its behaviour. But now we actually have a behavioural model and a name. We can call it an online "social distancing" tool which lets you interactively increase or decrease the number of people in your room (i.e. your stream or timeline) based on the strength of your relationship with them.
Works for me.