I was wondering the exact same thing. Just tried this today and noticed the same.
i am seeing multiple categories for relays, this makes thing a little confusing. there seems to be overlap....?
also wondering about these strange characters beside the left menu: https://i.nostr.build/bUkdss8yMWyLJjGc.png
another thing, if i paste an image into a new note over the demo web instance, it automatically hosts the image on nostr.build. But when I try to do the same with my own instance connected only to my own relay, it says "failed to fetch"