They also have transparent TVs that have an LCD layer on the back that can turn on or off to make it not see through.
It's stupid for a normal TV, but it would actually be cool for things like windows. Have a huge window with a great view in your living room and have your room setup around it. It doubles as a huge TV screen or a nice view of the outside. Also you could just hit a button and instantly make them opaque for privacy instead of needing curtains.
The downsides are it would be very expensive to make, and it would use a lot of power.
It would also be cool for window displays at stores. You would no longer need to put physical signage on the windows and can do videos and interactive stuff.
Can you imagine trying to play a dark stealthy FPS on such a display? Is that an enemy, or is that just some dirt on the back of your stupid transparent LCD? Iis that health, or is your wife playing with her bright phone behind your screen?