How do I set the interface to change the picture to be displayed only on this page！

Design help General
1

How do I set the interface to change the picture to be displayed only on this page, such as the one I marked with “√”
Picture 1

picture 2
picture 2661×811 85.6 KB

picture 3

Here is my site Read-Only: LINK
(how to share your site Read-Only link)