This page is used to create the loading indicator image. As old browsers and even new ones struggle with
complex CSS animations like box-shadow, it's better to create a GIF from this animation and reference that.
That's exactly what was done here. To change the loading indicator, record the animation and save it as GIF.
I used https://www.screentogif.com/ for that.

Reason to create our own loading indicator is that most indicator GIFs out there are not compatible with the
GPL license.