So can Lemmy users see Mastodon stuff as well? I've tried to look up stuff from Lemmy on my Mastodon instance and it doesn't work, but on my Mastodon server I can see my Lemmy account, but nothing on it.
I think you'll only be able to see your posts, and not your comments. So if you have no posts, you'll have nothing to show mastodon users.
One thing that I think is neat, and others think is a problem, is that you can @ tag any mastodon user with Lemmy and vice versa, and they'll get a ping and be able to respond to it and join the conversation.