The final feature of the diagram that I want to present is shown in Showing the Spiral arm of the 222 shell with the r..., the dotted red line connects all the 3 points of every shell.  This creates a the spiral arm that emanates out from the event horizon.  You can clearly see that there is a spiral arm for each number, and that as the numbers increase they tend towards becoming horizontal, and are evenly spaced.  These spiral arms also emanate in symmetry below the horizontal.