Traditional Culture Encyclopedia - Hotel accommodation - Turn off the light in the mirror of the hotel bathroom and get a red dot. Is it an infrared camera?

Turn off the light in the mirror of the hotel bathroom and get a red dot. Is it an infrared camera?

It may be a camera, or it may be an indicator light such as a power socket reflected in the mirror. You can point your finger at it.

Point to the mirror. Put your finger on the mirror. If there is a distance between your fingertips and the image in the mirror, it is a one-sided mirror. If there is no distance between the fingertip and the image in the mirror, it is a double mirror.

Network transmission can be judged by tapping the mirror and listening to the sound. When you find that the sound is hollow and there is a slight echo, then this mirror may be a double mirror. But it doesn't seem easy to tell the difference.