How can a mobile phone take a selfie to become a mirror image?

Taking Huawei mate 10 mobile phone as an example, the setting method is as follows:

First click the "camera" icon on the phone desktop, as shown in the figure below.

2. After entering the camera's photo interface, click the selfie symbol in the red box in the upper right corner of the page, as shown in the figure below.

Third, then slide the screen to the left to bring up the self-timer setting interface.

4. Turn on the "selfie mirror" switch in the setting interface to make the selfie mirror.