Just wallpaper. It will really open up & brighten that room with the light airy design. I’d do the paper before deciding to paint the cabinet if it’s in good shape. The cabinet might just look great & be the pop for the room & it will pull out the goldy / dark color design leaf / flower? that’s scattered throughout. The mirror you have goes with the paper too. I assume you’re staying with same color faucet. The window box top is nice & the fabric looks like it works with the wallpaper but it is way too skimpy. I’d have a window covering that extends the full width of the box top. So, my vote is paper first then fix the window drape part & stand back & reassess before changing or painting anything.

It isn't a "paper" , it's a mural .

You aren't changing the floor...... a much different feel than the airy/fresh of the mural. I'd be inclined to use a wainscoting, paint it a warm green, paint the cabinet SAME and use the mural above the wainscoting.

You will need lot less of the mural, $$$$ get the same freshening impact, and yet still "ground" a paper that might feel too airy and fresh with the flooring.

Lose the wood valance for a Woven wood shade, or a wide blade shutter? I doubt anyone can see anyone on the potty with the window elevation, unless a near neighbor second floor window?

New light fixture, please : )

I'd ask the flooring outside the powder room? A CHANGE of flooring opens a ton of other options

The flooring outisde the bathroom is the same in the hallway/foyer/den. Appreciate the feedback. Yes, defintley new light fixture.

Your choice of wallpaper is lovely.
I would consider removing the boxy thing oppressing the top of the window...it defeats the airy vibe of the intended wallpaper.
Wainscotting if kept simple will also enhance the overall eye pleasing aspect of this little gem of a room.

Hi Kathy ❤️ the print, certainly keep the wainscoting. Lovely

I'd give some serious thought to NOT using that wallpaper.

The white background doesn't seem to work with the flooring.

The wallpaper while lovely seems a bit bright/crisp for the space and I’d worry it would make the floors look dingy -

I’d do something warmer and more mid tone if it were me

It only works if you strongly GROUND it via visual

weight/beef and a color. A break from a more organic sink, a rather dingy tile as compared with the freshness of the paper.

Otherwise? Another selection in order, such a light and neutral grass cloth: )