IKEA - SCHOTTIS, Pleated shade, Easy to attach to your window frame. No drilling needed.Can be easily cut to the desired size.Keep the blind open in the desired position by securing it in place with the included clips.
This could work in a tiny bathroom. Love the tiled floor/painted wall combo and the fact that the tiles in the shower match the wall colour but are different from the floor. The niche for storage works well for us too.