subignition

After the point in time where you made the connection, you will see activity start coming in from their connections. So you should gradually see their followers populate as those people make new posts, which get federated to your instance through your connection to them.

Especially if the connection you made is the first time the remote instance has been interacted with, it’s going to look barren at first because there is basically no capability to sync history. You can think of it like an RSS feed.

(This is oversimplified - it’s possible that ActivityPub might allow for historical items to be synced just like RSS publishers can choose to include older data. I would speculate that it’s not commonly done for bandwidth reasons if it is possible.)

A downside to this is that if you’re trying to read through historical posts (from before you made the connection) you will have to click through to the hosting instance to get a complete view.

An upside to this is that because you only see content posted after the connection is established, you are guaranteed to be seeing new posts from active users.