As far as I can tell, it’s not lemmy’s problem, it’s mastodon’s.
Lemmy can’t control how mastodon presents the information that lemmy shares.
And mastodon does a bad job of formatting lemmy content because mastodon is actually a fairly minimalist (I’d say brutalist) platform. No text formatting. No threads (well now they have minimal threading). Only one feed type (equivalent to “new” on lemmy). And communities and groups aren’t processed as groups, but just like users that boost/re-tweet everything in them, which is not what groups actually are at all.
This is the fundamental problem with the promise of the fediverse … platform inter operation is not guaranteed at all as there’s no clear path to reaching common ground on how to format every other platform’s content. The protocol has nothing (or very little) to say about that. Then, once you have a bunch of platforms, you’ve got a lot of work to do, as each platform needs to workout how to render every other platform’s formatting. For N platforms, that’s basically N^2^ formatting projects.
In reality, federation is mostly an inter-platform system. For the moment at least. It makes sense that at some point one’s “window” onto the fediverse is capable of understanding any format you want and will render everything as it was intended. Instead, at the moment, the fediverse is running like it’s still 2010 and the cloud is still new and cool and having users on servers is the only way to do things so that we’re all still stuck on servers/instances and bound to their admins and applications. IMO, it’s hardly living up to the promise of the internet, and hardly doing to social media what the internet did to computing.
With the internet, I opened my browser and visited any webpage I wanted to see it as it was intended by its author no matter who wrote it.
With the fediverse, I visit one webpage and see any post I want, so long as it doesn’t come from a defederated server (which can be a problem sometimes), but only in the one format that my one webpage/instance has decided on, no matter how it’s supposed to look and indeed does look if I were to view it on another webpage/instance. When the browser is over 30 years old and PCs around 50 … this feels unimaginative to me.