What's the output during PyPy build means?

Question

During the building phase of PyPy, the script produces some nice ASCII characters that looks really interesting. What does each character represent? How to interpret this output? What really is PyPy build doing while producing this ASCII art?

Answer 1

This is the mandelbrot set.

Enjoy Mandelbrot :-)

according to http://pypy.org/download.html . This creates an enjoyable build experience.