Do you have a source on who made those? They're pretty fascinating and I'd love to learn more about how they were made.

Some redditor, apparently: https://www.reddit.com/r/etymology/comments/1pxjuh/interesti...

He also posted a video of the work being created. Wondering what tools he used to make it.

https://www.youtube.com/watch?v=rUCVBNNyjC4

Interesting that the authors don't mention the book Mirror Worlds (https://en.wikipedia.org/wiki/Mirror_world), but the last line of the article does make an allusion to it.