Fun visualisation, but I don't see that one as being particularly useful (what does it really represent?)

As someone who has looked through many different types of files in doing quite a bit of RE, I've become able to separate out different types of data just by the "feel" of how it looks in a text editor; Z80 and 6502 code, x86, MIPS, ARM, bitmap images, and compressed data all have different "textures" to them.

It represents randomness(entropy) in the firmware file. And "known" file types found in the firmware file.

It is very useful. As different file types and data structures. Often has a quite common entropy level to them.

Rather than doing it in your head as you do one can use a machine to help, which happens to be the hole point of machines.

I'm talking about the animated one in the parent - AFAIK entropy is a scalar, not three-dimensional.

Oh the animated one, yeah you are correct that is not entropy at all.

It is just bytes visually represented. 1byte = x axis, 2byte = y axis, 3byte = z axis. And then jump forward and repeat.

What is RE and where can this tool be found?