Is a citadel supposed to look like that?

[Blofeld]

Happened to me twice in 1 game: I watched a battle replay from a citadel assault, the citadel had a very strange graphics: some disconnected walls and grates. Defenders started in the open.
See attached picture for details.
Can anybody tell me whether ii is a bug or the citadel is supposed to look like that?

[Nerfix]

It sure looks like a bug. O_o

[Taqwus]

That's quite an interesting architectural style, but it would probably be a wee bit drafty for winter.