For maximizing privacy and still allowing light, I really like the "top down, bottom up" shades. Ours is from Hunter-Douglas, it's pleated, the "Duette" version, it allows soft diffuse light through when fully closed. We usually keep it in a partial "top down" mode, so the bottom of the window is covered but full natural light can come through the top. This photo shows "top down" on the left windows, "Top down bottom up" on the one second from the right, and "bottom up" on the right. Very versatile. No mold/mildew, ours has been in for 15 years.

I'll make the simple blanket statement that I'm a huge fan of top-down-bottom-up shades in the bathroom, especially over a tub. The top-down function is especially valuable for allowing natural light while still affording privacy. If you have bathroom lighting that can result in silhouette shadows being cast on the shade, the honeycomb cell type of shades are great at diffusing shadow lines. I'm no designer, but I'll toss this out and let those with the eyes for pretty things hash this out...would those windows and walls benefit at all with longer shades that can extend down beyond the window sill and just cover the top of the wall tile? Or will that be too sloppy?

I’m no expert on window treatments, but I think Roman blind or cafe curtain here. I had a similar dilemma with some inswing casements in a bathroom, and I resisted the idea of window film. Then one day, I gave it a shot, and wondered why I waited so long! It was a perfect solution (for me,) and the entire roll of film was under $10. Just a thought—you’d have very little to lose, though you want a steady hand when you apply it. Also: that is a beautiful tub! So elegant. And one more thing: may I ask what us that green thing out the window?? good luck!

I love my plantation shutters, but you are right, it would not be an option. Years ago though, I recall bi-fold shutters, but in your case I don’t think it would work because it’s too close to the vanity, and it wouldn’t look good either. We did something unusual for my youngest who lives in an apartment in the city. Her window looks right across a courtyard to a music school. We put a blackout shade behind a venstain blind. She has so many options with this scenario. What if you put a plain window shade behind the Roman? The Roman can stay up most of the time, and you can just pull the window shade down at night. For me, easier then the contraption of the Roman. It is true that you never know who is looking and out on their deck at any hour. Certainly not saying they are doing it purposely, but, you want to assure your own privacy. Personally, I never turn the bathroom light on in the middle of the night. We have a nightlight that throws off just enough light. Could this be an option? When a home next door to a friend was being rebuilt to something bigger, she went to view the home to how see what views the new people would have looking into her rooms. I would never have thought to do that.