well, a big dragon DOES pop out and shoot stone fire
No, it doesn't. That dragon is not part of the mural, it's overlaid on top. The fire is, too. There are distortion effects and yes, there's a CG dragon, but as far as I can see it's all
added to the mural. Nothing in the static image actually changes.
Anyway, I wasn't asking for speculation. I'm looking for the Bethesda tag in replies, and I don't see it yet.