I personally think the email analogy does little to help.
What if federation is described as posts, comments and votes syncing between servers? This could make more sense to some people, and make it easier to explain some federation quirks (“this server stopped this other server from syncing with it”, “Votes differ slightly between instances because they are still syncing”)
What do you think?
I think the issue is that the use cases for email and Reddit vastly different, and so saying “Lemmy is like Reddit but also email” can be confusing to new users.
Saying something like “you can participate in almost all the sublemmys no matter which Lemmy website you sign up at” would be more useful.
The email analogy is fine to explain “what is federation?”, but new users don’t need to understand how federation works in order to try out Lemmy.