I had to read the article several times, I think 3 times or so, coupled with reading some other articles alongside it just so I can grasp this concept. It interesting, the concept shadow is faster than light but in a way that doesn't seem to break any universal speed limit. If you move a flashlight 🔦 rapidly or shine it on surface at a considerable far distance, you almost see the shadow appear just before the light but no universal speed limit is being broken. You can try it
I believe there is still more to this concept