Comment by saagarjha

This reminds me of the last time I was in Vegas for DEF CON and we booked rooms in this dimly-lit hotel that had surprisingly bright bathrooms with a floor-to-ceiling mirror in the shower. A similar mirror hung outside in the room on the wall opposite.

Yes, it was a one-way mirror looking in. A number of people who had booked rooms together had an exercise kicking their roommate out of the room to take showers that week.