I think some of us are talking about the focal point and some are not. I was talking about the focal point staying the same, but lasersafe1 is right that it changes the shape of the cut. If the circular beam hits the center, you get an hour glass shaped "kerf" through a thick material. If the beam is off center you still get an hour glass shape, but it is at an angle. This will affect the shape of the kerf, making the cut at an angle. There are lens aberrations etc that affect the focal point but not to the extent shown in the pictures.
it will steer the focal point
might be better said...steer the beam.