thanks but from what i see on the neighbouring houses, the sticker doesn't seems to work at night. most of then will still need to hang a towel or cloth to cover it up 

opaque film shall do the trick but then i'll need to let go the natural sunlight during day time. want to try to keep this if possible 
ya considered this but since it's just next to the shower head, may i know will it be easy to clean? and will it get dirty easily by the soap scum?

if possible, would appreciate if you could share a picture of your set up?

thanks