Why?
I personally kinda like it, its an indirect hint that my relays are still connected.
Discussion
Annoying I guess?
it's extremely distracting and you can't make it go away
If you click it you lose your place in the feed, then it pops back up 2 seconds later every time a new post lands. I know how to see new posts, click the home button. I know when there are new posts to see: always. If you simply must add a graphical element indicating there is new shit to see put a little dot on the home button. This would also annoy the crap out of me but at least it doesn't cover up the main feed.
The reason this feature exists in twitter is to keep you engaged. You get a little dopamine hit every time you click it, twitter gets more clicks and therefore more ad revenue. There is no reason to do this in nostr. It doesn't even make sense. It's just aping features from the legacy social media clients.