While working on the Emacs Network Security Manager, it was suggested that Emacs implement a visual hash for certificates. It turned out to be a not-unproblematic idea, so I didn’t do that, but by then I had already written an SVG library.
While staring at it, it occurred to me that it would be kinda neat if the image created would update in real-time.
So I did that.
I think this library will probably end up on GNU ELPA.