You got it wrong unfortunately. We basically interact with a copy of the federated instance, that lives on lemmy.world. Each change or comment we make gets synced with the true instance and vice versa.
Which also means that if a single user causes for example a child porn community (I don't care if it's drawn or not, I don't discriminate between pedos) to be federated, we would now be hosting child porn on Hetzner servers located in Germany and Ruud would be in pretty serious trouble.