About the "git merge" tee-shirt

Hi,

For those of you who weren't at the Git Merge conference last week, we
goot a tee-shirt with this drawing:

https://drive.google.com/file/d/1v9bfY0mI8Hi94m4SgqLccFnZ5L_OUlaJSA/view?usp=sharing

I have to say I love that tee-shirt. I already had tee-shirts that only
computer scientists could understand, now I have a tee-shirt that not
even every computer scientist can understand.

Now, I have a problem: I'm not sure I understand what the drawing
represents.

Initially, I thought the circles represented Git contributors, and links
represented people contributing to the same parts of the codebase. But
looking at the output of "shortlog -s", I can't find a correspondance
with the tee-shirt. My second guess is that they represent directories.
But even then, I can't find which of the tee-shirt's circles represents
which directory, and the count doesn't match.

Does anybody have a better explanation? Or is it just a random drawing
to say "Git is bigger than it used to be"?

Thanks,

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/