I'm seeing within Sync a number of users have profile pics that show up on their posts. Is there a way in Sync to set that?

So, I'm new to the fediverse and Lemmy, and I'm still trying to wrap my brain around it all. I'm sure people have talked about this, but by far my biggest issue so far has been finding communities. I specifically didn't want t to join a large instance, but that has led to issues of finding communities. I often need to go to lemmy.world or lemmy.ml and search for communities there because searching on a smaller instance won't yield results if no one's subbed to that community, even if the instances are federated.

Which leads to the point I'm trying to get to. It feels almost to me like if I'm trying to search for a URL but the DNS says it doesn't exist because no one on that DNS tried accessing that URL before so I need to query another DNS for it. But in reality, if I ask my DNS for a URL, if it doesn't know it, it'll ask other DNSs in turn until a result is determined. Why can't something like this exist for searching for communities? Does something like this exist at all, or is it impossible / a limitation of activity pub? But I feel searching for a community in one instance should in theory, if it doesn't know that community yet, be able to query federated instances if they know, until a result is returned.

Apologies if I'm unintentionally beating a dead horse. Or if there was a better community to post this to other than this one. See aforementioned community finding issues, lol.