timing maybe? perhaps stuff sent closely together in time is clustered together, but I am guessing.

there’s also a “Compact” theme if you want to get rid of all avatars — at least those next to messages

We try to encourage folks to use threads as much as possible so you shouldn't get multiple posts by the same person in a channel. It makes it much easier to have multiple conversations going on -- and prevents exactly this sort of noise in a channel.

That makes sense. Thanks for encouraging high SNR.