Its probably a "wet" bathroom so fully tiled and a correctly installed floor drain so no shower curtain necessary. If they are done properly they work really well and a dream to clean - just hose it down. Having the loo in there too isn't unusual in Europe anyway. If you need to pee while someone is taking a shower, use the kitchen sink. Duh.
Yes, the bed and stairs are dangerous, impractical and stupid. I hate having to climb over the bed in order to get in/out of it.
It's clever but having that separate hallway seems an unnecessary waste of precious space.