The windows on the door of the bathroom in many Israeli apartments (not all), are opaque windows that cannot open, and I think the reason is as cherry bim said, so light can get in and you don’t need to turn the light on (saves electricity), but I’m not sure.
Toi — that is intentional — it is to allow steam to escape and air to circulate to help avoid issues of mold. (You are supposed to open the window after the shower so the bathroom dries out.) This is similar to many bathrooms that have venting fans for the same reason.