Can you post a picture? How big and how low is the window? First or second floor? We have an older home (1937), so our bathroom windows are pretty small and set fairly high. En-suite bath and powder room face the street, another with window in the tub/shower faces the driveway. We have six pane windows on the 2nd story baths, and have film only on the bottom four panes. We have an all-over small crinkle film that is not see-thru at all? If you have a very large, low bathroom window on a first floor, though, you may need some kind of a pull down shade.

Pictures are indeed welcome! Can we see the shower for which you’re wanting suggestions?

We used a tension rod and shortened (cut) a shower curtain liner. Been working great for 6 years now!

have you tried film from stickpretty.com? It claims to offer 24/7 privacy.

You can get pvc shutters that look good and are easy to open and close.

I checked the stick pretty website. They say their films are translucent not opaque

PVC shutters seem like a good option

The window placement is definitely unfortunate. Did you build this home? If not, just curious what previous owners had covering the window.
I agree with above posters on shutters in a PVC. Could do entire window or get cafe style to cover lower portion. I fear any type of shade wouldn’t do well inside a shower

Have you actually tried a window film company? They definitely make film that will do what you are asking for.

What is outside it?

We have a tension rod with white curtains, which we cut down to fit, in our bathroom. We also have inner shutters (which don't shut because of the tension rod).

Wallpaper for windows. Easy to apply with water (sticks with static cling) and can be removed anytime. Ours in the bathroom looks the same as the day it was applied 22 years ago. Full privacy. Here’s our front door

Roller shades are a great option and can provide the privacy you need while still allowing light to filter through when not in use. Another option to consider is frosted window film. Unlike translucent films, frosted films provide complete privacy while still allowing natural light to enter the space. They are easy to apply and can be cut to fit your window size.Before making a decision, it's a good idea to consult with a window treatment professional to explore all your options and find the best solution for your needs. Check out https://www.prsolarwindowfilm.co.uk/ for more information on privacy window solutions.