Another question about how lemmy works

I am on lemmy.world. In the last couple of days, I've been flooded with "comicsoutofcontext" contents. Nothing wrong with that, but why?

Some other times, it will be nsfw contents. And the next day, some other random community will flood my feed. Nothing wrong with that either.

But, I don't understand how this all works. It seems that the priorization algorithm sometimes goes wild. Or maybe there are only hundreds of users actively posting and when some guy posts a batch, I'm flooded with it?