Reducing motion with the picture element
I always associated prefers-reduced-motion with CSS, but of course the picture element accepts media queries!
A quick post from Brad showing how you can use the picture element to serve up a static image instead of an animated gif when the "reduce motion" preference is enabled.
Examples like this are why I love how the whole suite of responsive images standards (srcset, sizes and picture) turned out. I know some weren't as pleased with the final product, but there's so much darn flexibility (ahem) here to enable us to account for scenarios, like this, that only really emerged after those standards were created.