Hello, I am trying to understand and rotate the placement to that of Southerns example. I thought I understood that the light or dark sides of the sphere did not matter. I managed to rotate it attaching an additional sphere and rotating it down. Howerver deleting the control sphere abandoned the rotational movement of the zsphere intended to rotate. Can someone please help me. I am extremely pleased with the potential I find in ZBrush2. I am attaching an image to illustrate my intention. This is not mine. It is that of Glen Southerns.
thank you
Joseph 
Just pass in Edit mode
Press “R”
Clic on the Zsphere
Kep the mouse pressed and move it!
The ZSphere will turn in any direction 
Pilou
ps
If you press an “inter sphere”, it’s all Zspheres over the “root” who rotate !
Pss Play rhe tut inside “Zspheres”
I’m not sure I completely understand what you’re asking, but what I think you’re asking is why that “forehead” sphere is rotated so that the white side is to the front while the rest have the white to the back?
Usually that does matter. There would be a twist in the middle of the head, unless the ZSphere by the “mouth” is the root sphere and the ZSpheres were made on the opposite halves of the root ZSphere.
I 'm not sure how I can explain it easily, so here’s a picture:
The child Spheres must have been made on different halves of the root ZSphere so that they don’t produce a twist… That’s the only explanation I know of (I am still new, so I could be wrong.)
All Zspheres can rotate at any level !
The result depend of the level
Root, children, children of children, etc…
Even inter-children
Pilou