I have seen frameskip on pixel2 as well on YouTube videos when they review the pixel 2 so might be how it is?
imo, It's not actually a frame skiping. You can see it here.
https://imgur.com/gallery/0ev7P
Maybe it just what he said in FQAs. The wallpapers are made for Snapdragon. But damn, I really like the Lagos one and I still hope someone can make them run smoothly on Exynos.