I pinged every IP address that wasn't reserved. The image is 8k by 8k and is re-encoded as an AVIF to be friendlier to mobile devices. Like every other survey done, it is using a Hilbert Curve to convert the linear address space to a contiguous 2d space. The hotter the colors (blue is coolest), the denser the ping responses were.
(If you are interested I can provide the full-resolution pyramidal-tiled TIFF (about 1 GB) that requires ~3 GB of RAM to view. I've also compressed the ping response data into its own format down to about 150 MB. PM me for a link)
Here is a 2006 survey to compare.
Some observations: Big Tech (USA) is in the top left. US government allocations, for the most part, did not respond to any pings. And maybe you didn't realize this before, but Multicast (Class D) & Class E consume a whopping 12% of the IPv4 range.
IPv6: a dark image