How do people decorate the little windows in or above the shower?

Grow orchids! Not only will they love the humidity and warmth of the shower but the light from the window should be perfect growing conditions.

I made a 3 inch valance with 1 inch on top and bottom. Put the spring rod through the center and put on inside of window really nice and different

Keep it simple! I love design that can be strong with it's architecture, and doesn't need a lot of "stuff". A simple window valance. or nothing, if the architecture of the window is strong!

I have a valance that matches my shower curtain on mine. (You could do a full curtain too,)

Since I want the natural light coming in, even though the window is literally a hole in the wall, no architectural detail whatsoever, (mid 80's box as I refer to it), I put a few tiny plants up there. When they get too big, I just repot and start over.

Hang small glass stain frame in front of it.

Some people put artificial greenery there and forget it.