The data lives in both places. Your pod is all of your data held in one place. The interaction is a copy of that data sent in and out to the various social networks.

I would expect that you could adjust how much context to save around your comments. Maybe it pulls down the while thread on whatever service, or maybe just the comment you replied to with a url.

This is a bit of a deviation from the initial “Solid” concept, as that was a fully standalone controlled data warehouse that you allowed social media to access only during using the service. It was a way to have control of your data because you hold the data instead of social networks.

With the fediverse’s replication between different hosts, there wouldn’t be a way to gate this data, so the concept looks like it was adaptived. A big advantage for the fediverse? Your account is actually on you pod, not someone elses server. The data is replicated via the servers is all. You would basically be “federating” your identity with a server, not depending on it.