Well, I have a guess:
So
this is the Starminx.
The Starminx I,
as you can see here, has the same lines and outlook, but turning a side is further from the center.
However,
in te case of Starminx II, turning a side is deeper, affects more elements.
That's why I thought the definition of a deep cut is something like this, turning a side is somehow deeper than the shallow cut version.