Comment by andrewmcwatters

Yes! And it was frustratingly patented! https://news.ycombinator.com/item?id=34937618

I suspect that their new technique implements the existing fast gaussian blur, and since the patent is about to expire, it was a good time to spice it up.

I suspect as others have mentioned here, they use a "Liquid Glass" shader which samples the backing layer of the UI composition below the target element and applies a lens distortion based on the target element's border radius, all heavily parameterized so as to be used with the rest of the system's Liquid Glass applications like the new icon system.