Hey There: You do have plenty of options when it comes to window treatments for small windows. Choose an inside mount installation - this leaves the beautiful casing of the window visible and will also "protect" from shower splashes. Bottom up - Top down pleated blinds with no pull strings is a great solution (no pull strings!). You can operate them directly on the horizontal metal bars and adjust them to privacy and light. Opt for a fabric that can handle moisture too...

Good Luck

I also prefer cellular shades for the bathroom

Try Decorative Window Film.

If you like the idea of something easy care but also decorative and easy to change, consider one of the newer decorative films which you'd cut and press in to your panes, using a professional grade xacto type knife. Simply pull to remove, no glue.It's an easy DIY and some provide complete privacy without blocking all light. See photos. We've used both films shown to great effect and the price is right. We did one set of bathroom windows for $12.99. A company called Rabbit Goo makes these as well as Blize or Bluss.m