Why does the Xiaomi MIX Flip’s external screen use mirror mode when taking photos?

The main usage scenario of the Xiaomi MIX Flip's external screen is selfies. In order to ensure that the preview and imaging are consistent when taking selfies on the external screen, the selfie mirroring of the external screen is forced to be turned on. If you need to take pictures of text content, it is more convenient to use the rear camera of the internal screen.