Recording a video from a front camera, why is the result a flipped video, and not like the preview?

In fact, the preview video is really the flipped one. When you look at any mirror, the image is always reversed. As you can see, the front camera preview shows the world like a basic mirror. All other people see you from “a different side”. If you shake your right hand in front of the mirror, it looks like you’re shaking the left one. In video footage, this would make a distortion because viewers don’t consider it as a mirror. It could also bring some other problems. For example, if there’s any text in the background, it would appear backwards if the video wasn’t flipped back to normal.

It’s kinda difficult to explain clearly, but hope this helps!