Standard humanoid containment cells I imagine are fairly boring in the sense that you probably could tell the difference between one and a high security prison cell in the real world.
Strong walls, no windows, heavy doors, access points for delivering food/items without opening the main door, visual and audio surveillance system installed discretely to avoid tampering, and lighting and emergency lighting. Also some basic furnishings such as a bed, toilet, sink, chair, etc, though these would probably be fairly spartan and sturdy so as not to aid in any negative behaviors such as breaching containment.
Also, I'd imagine that the design would have room for simple additions and variations as needed for the unique properties that a scip might display.
