Maybe he doesn’t have a wallpaper installer and doesn’t want to look for one. I did see a room that had mold on wallpaper but it was b/c of poor plumbing installation. Nothing to do w/size or purpose of room. Wallpaper away! ETA: and regret it if it ever comes time to remove. I’m still shell-shocked from removing paper from kitchen, and it’s been a few years.

OMG, I just checked in here and wow. Ok, so you are not going to make this easy. Beverly, that vermicelli is delicious. Especially in the gold, but not right for this space and "he" will never unsee the other "thing" (but the style is so me). Jpp1, I get that. Trust me on this one. This place is eclectic! But you make me think about how the transition from outside the powder room to inside is a great opportunity. Chispa, Oh my, what is that first one? AND the 3rd? Love them all but started thinking dark (like the 2nd) and made myself crazy. The fourth has green and we just have a thing about that given the rest of our space. BUT THAT 1st ONE and 3rd??? Love group think!

I guess we all tire of the finishes, etc... so seeing your window handle, what about some sheen like here? yes... might be good option for a tiny room, and narrow/tiny sconces.https://www.houzz.com/photos/contemporary-shaker-kitchen-transitional-kitchen-manchester-phvw-vp~40851331

Since it's just a powder room and no shower, I would do all wallpaper. Take advantage of no steam and make something impactful. Love the idea of a red vanity too. Powder rooms, in my opinion, are a place to really let loose.