@AracasDragon

It really depends on which accounts you're looking at and from which server.

Once one person on your server follows an account, that server starts "noticing" what that account does including posts etc. These then become visible to everyone on that server from that point on.

The alternative would be all servers cloning all messages from all other servers, which is impossibly expensive and mostly redundant.

Backfilling would be a good compromise solution: https://github.com/mastodon/mastodon/issues/34