One of the Hotels I stayed at in Hong Kong was the Empire Hotel in Causeway Bay. The room was very nice and had a glass wall between the shower/bathroom area and the main part of the hotel room. I’ve stayed in lots of hotels that had showers like that so I didn’t think it was too interesting at first. But then I realized that there was a extra light switch in the bathroom and when you flipped the switch the glass wall instantly turned a opaque white. Pretty High-Tech!