I think the walls were rubbery and looked like built in closets. The bridge was too big and misshapen like Picard's head.
I've never been a big TNG fan and I hated the Enterprise
-D bridge design, but I don't see anything wrong with the shape of Patrick Stewart's dome.
The TOS bridge did look like a third grade classroom with the pictures of classic nebulas on the screens, but.. I guess they were screen savers.
Very rarely, images would be back-projected onto one of the bridge perimeter screens (as in "Squire of Gothos"). IIRC, the effect was seldom used because of the time and expense of rigging slide projectors and because union rules required a man on the set just to operate the projector.