Seeing that you already have a rod in there, I thought these would be good options.

https://twopagescurtains.com/products/sara-le-print-linen-cafe-curtain-pleated

https://pepper-home.com/products/cafecurtain-linen-flour-custom

These are bottom-up top-down pleated blinds that allow you to manage light and privacy in a bathroom. Only 1 inch in overall depth, these minimalistic blinds have no header nor strings across your glass. They are also suitable for wet rooms. Check them out at www.fenstermann.com or here on Houzz.