Quick guide on usage, for example beehaw.org, beehaw.org is in the orange bubble and therefore is federated to all instances in the orange bubble. Equivilantly, lemmy.ml is in both the orange and the red bubbles, and therefore is federated to all instances in both bubbles.
Mocked up in ms paint ðŸ˜
So if I get this right, from your body description: An instance A that is federated to another instance B will itself forward on that content from B to all instances federated with A, even if all other instances intentionally block federation to B? Or does federation only work instance-to-instance and is not relayed via 3rd party instances. Still learning the fediverse technicals right now.
Its not relayed, for example, on lemmy.one I can't see content shared by lemmygrad users, or see any of lemmygrad communities. Despite the fact that we are federated to lemmy.ml which is federated with lemmygrad.