This enclosure is actually on the second floor (unhelpfully denoted as San Ceng (C) on the map), however the viewpoint here is from the third floor (Si Ceng (D) ). The beam is presumably structurally integral to the building; why the windows are so small I couldn't really say, but I'd hazard a guess that it's to give much more control over the environment.
Map - ZooChat (This specific enclosure is C2, which in fact contained spotted seals not walruses)
Yes, I think it's basically an attempt to replicate the Haichang Polar Ocean facilities on a smaller footprint. They have their own problems, but this has just elevated them to another level.
