One of the side-effects of cohost's design is that there are ghostly conversations you never entirely see all of.
They could be in tags you're not following, or from people you don't know. Clearly present, but intangible.
Like I've seen a number of discussions where people are annoyed at those taking 'victory laps' over the revealed problems with Stripe, and I'm sure those a) do exist and b) are awful.
It's just another example where the day to day life of the site can be informed by Presences that make themselves known indirectly, like the place is haunted by opinionated shades.