I'd leave the window over the sink plain. As it is now it looks like a beautifully framed pic. I wouldn't cover it.
The two windows on the sides I'd go for for something that would go floor to ceiling to balance out the large scale stuff in that room and to make those windows look large than they are. A tone on tone that plays off of the tiles.

I did inside mount plantation shutters in my bathroom. I like the clean, finished look and ease of adjusting them for light and privacy.

I know the one picture is dark, but the large window is over the tub~ and even though the area outside is vacant currently,and it is a very pretty picture- eventually something might be built there within seeable distance.

First of all, your bathroom is GORGEOUS!

If you do go ahead with fabric Roman shades over the two single windows along with plantation shutters in the tub area, you could tie them all together by doing a mock Roman shade that matches the look of the other functional Roman shades when they are pulled up. It is basically a valance but looks like a Roman shade pulled up, if that makes sense. Hang it high so the bottom barely covers your window view.

I like my windows completely uncovered. Only cover them temporarily from the sun or for privacy. I would use some Hunter Douglas duette type shades that match your trim. They now have a "lineny" fabric called Batiste that is nice. Do the top-down/bottom-up option for more flexibility. You could do the battery operated model over the tub, so you use a remote and don't have to climb into the tub. I just replaced 30 wood blinds, with a few more to go, in the house we bought recently ... did I mention I like my windows uncovered!!

meowzer- thank you.. we like it a lot!

Your idea sounds interesting.. have you ever seen this done? Any pix to share??

Hoping to get picture ideas.. I have to see to believe!

I would do plantation shutters on all of them.

nini804 - That is my husband's preference! Maybe I will do that.. but I think I would like to see a little fabric.. but all plantation shutters would make the decision easier!

Yes, I custom designed a mock Roman shade for my mother based on a totally function Roman shade that I made for myself (see 4th pic below). She loved the way it looked pulled up, so here are pictures:

Not yet installed, still lying on the floor (approx. 16" long):

Sorry for the poor lighting where it was installed. It is hanging about 8" higher than the window frame, barely covering the top moulding:

Another one for my mother in a different room and different fabric:

This was the her inspiration shade which is a fully functional Roman shade covering a window about 65" tall and 29" wide frame to frame:

I used Simplicity pattern #9986, but had to adjust for a smaller width and longer length.

You could also Google "mock roman shade" to see other styles. It will depend on the ACTUAL shade you choose and then design one to match how it looks pulled up.

I personally like roman shades in bathrooms - enclosed in the window like this:

[contemporary bathroom design[(https://www.houzz.com/photos/contemporary-bathroom-ideas-phbr1-bp~t_712~s_2103) by san francisco architect Schwartz and Architecture