^ Are you sure of that?
After the first two pushes we have something like this:

When viewed from top it is a rectangle, when viewed from front it is a hexagon. We now have to push the 8-nal cutter from the left to the right.
But what size should the octogonal cutter be so that the remaining figures stay the same? If it's smaller than the rectangle, then the hexagon will not be hexagon anymore. If it looks somehting like that (view from left):

then the hexagon's corners will be cut off.
Am I right?