Lemmy is the fediverse link-aggregator, like Reddit

Mastodon is the fediverse microblogging platform, like Twitter

On Lemmy you subscribe to communities, but on Mastodon communities are essentially hashtags, so you can also follow users to get updates directly

The kind of person buying a Mini I would bet is closer to the kind of buyer that has historically bought the SE

I upgraded from an SE to a 13 mini

lemmy.world status according to this thread