[alanbernstein]

The colors and the sliders are both a bit extraneous to the point of the visualization, they're supposed to help but they kind of obscure the point.

For the northern landmasses, Greenland for example, the smaller outline is the equal-earth-projection, and the larger outline is the conventional Mercator projection. That's all there is to it.

[bitparadox]

I just viewed it on desktop, and here I can see the inner and outer outlines. On my phone I studied the diagram closely, but can't see the inner map outlines. Perhaps just a color profile thing on my phone.