How did Apple delay taking pictures for three seconds?

How to set Apple's three-second delay camera;

Tools/materials: iphone 13, ios 13, settings 1.0.

1. Enter the mobile phone camera and click the small arrow at the top of the camera to enter the secondary menu.

2. Find the timer-style icon in the secondary menu.

3. Select the time we need to delay in the timer function, and click the shoot button to keep the phone still. After the timer is completed, it will automatically shoot.