Well, I think it's showing a decentralized network, not centralized. Maybe closer to federated, who knows, it's not clear. It's for sure not distributed though, while IPFS is a distributed file system.

If the graph contained at least one other link between the nodes than via the center one, it would make it more clear.

I think this famous graph (from Paul Baran https://www.rand.org/about/history/baran.html) does a good job of showing the difference: https://ipfs.io/ipfs/QmdYtMUTnz6vaQNRUAzhh8YiSSGzBCyQrCXE5Ag...