SolidPointOn: it's a bug?

Rhino Rhino for Windows
1

Starting from the first figure, the active solid points;
moving a point in one direction happens what you see in the second image.
It is a bug?

2

Who could you tell me if this is a bug or a limitation of Rhino in the deformation?
Thanks

3

limitation , this tool will work only on very basic shapes .

4

Thanks Cyver.