About the Box Mode
The Box Mode is a display mode in Freestyle where the control mesh is shaded instead of the B-Spline surfaces. It allows you to perform fast and complex manipulation of the mesh, because surfaces do not regenerate in the Box mode.
You can switch between the Box mode and the Standard display mode by clicking 
on the in-graphics toolbar.
on the in-graphics toolbar.
1. Shape is shown in B-spline standard mode
2. Shape is shown in the Box mode