If I click on certain images, Discourse animates zooming the image.
This zooming animation can trigger migraines. Google Maps is a worse example. Either removing the animation, or checking for prefers-reduced-motion and using that as a cue to skip the animation, could be safer for users with these migraines.
Yes, I think we should use prefers-reduced-motion here, that makes sense. Thanks for the suggestion!
Thanks a bunch for bringing this up 
The zooming should now be eliminated if prefers-reduced-motion is set on your machine with this PR. "A11Y: Add prefers reduced motion" by jordanvidrine · Pull Request #14859 · discourse/discourse · GitHub