How does Xiaomi mobile phone add pages to the desktop?

Taking Xiaomi 4 mobile phone as an example, the specific operation includes the following steps:

First, when the mobile phone is placed on the desktop, draw the center of the screen with three fingers at the same time. The specific operation is as follows.

Secondly, all home screen thumbnails will appear on the mobile phone desktop, as shown in the following figure.

Third, finally click the "+"sign on the interface to add a desktop page, as shown below.