How to clone GitHub Wiki images that were auto-pasted?

I’m using GitHub Wiki pages. I’m using Asciidoc, but I don’t think that matters. When I drop an image into the Wiki editing area, it makes a URL like this:

https://github.mycompany.com/ORG/repo_foobar/assets/402/773e8fc6-4278-4dbe-ab88-73dde53963ab

The core of that is the “assets” element. What is that? And how do I clone it?

I know how to clone the Wiki, and that gets me all the *.asciidoc files. But not the images.

If I clone the main repository, I don’t get anything like “assets” nor do I find anywhere all the *.png files I’m pasting.

I know I can put images in an explicit area of the code, then it would clone fine, but that’s a lot of work compared to the very easy pasting.

How do I clone or otherwise back up all the images that are referenced in the Wiki?