Without actually digging into it, I would assume that nytimes loads js assets from a third party, that's the direct nodes from the center. The size of the more is the size of the js asset. That third party then injects yet another script onto the page. The next connected nodes represent these scripts and their size. And so on and so forth. These scripts ensure to the advertiser that their ad is actually being shown. The advertiser doesn't trust the hosting page to correctly display their ad, so the ad injects their own tracking script. That tracking script injects their dependencies. Thus this madness.

Every blob on the map is a loaded resource and an line connects every resource with whatever pointed to it. The reason you can get a tree is because of things like iframes that can then themselves request other resources. It might also be some 3rd party javascript requesting other third party resources.

This is obvious but I had Firefox containers & Decentraleyes enabled. This makes comparing the results to the output of the DevTools Network tab a little difficult.

Turn off all the protection to see the issues in the DevTools Network tab.