Hi there,
In this case, it’s actually easier to use CSS than the Customizer.
Every page has an ID, you can see it in the address bar when you’re editing the page. You can also right-click the page and click “Inspect”. The ID will be in a class in the <body>
element.
So for example, the ID of your About page is: 964
Using that ID, we can do this:
.page-id-964 .inside-article {
background-image: url( 'URL TO YOUR IMAGE HERE' );
background-repeat: no-repeat;
}
Let me know if you need more info ๐