Visual explainer of empirical Neural Tangent Kernels

There is a new mech interp method in town. I found it difficult to get my head around at first, but once I understood it, I found it beautiful. I am not an expert in this topic, and mostly write this up for me to get some intuitions, so there might be mistakes here.This explainer came out of summarizing the paper Feature Identification via the Empirical NTK by Jennifer Lin. The (empirical) neural tangent kernel itself has been in use for a while, but this way of using it for mech interp is new a...