Double Toblerone!

Why does nestling an absolute function within another absolute value function (as shown below) produce what is seen here in this screencast? Note: Composing 2 functions with an absolute value function serving as an inner function can, at times, be a means to produce duplicates of graphs of functions (in 2D) and surface graphs (in 3D). For more info, click here.
[size=150]Here are the surface equations used to create the double Toblerone model shown in the 3 app below.   [/size]
Here are the surface equations used to create the double Toblerone model shown in the 3 app below.