And this is where federation and interoperability becomes nice imo, because one doesn't have to use pixelfed and can still get content from Pixelfed in their Mastodon feed, if they want to.
Say someone would like to see the content of just a few Pixelfed users, but doesn't want to create an own Pixelfed account just for that, one can just to follow those specific Pixelfed users with their Mastodon account to see the Pixelfed posts in their Mastodon home timeline.
Kara