The torque parameter is created with respect to a selected axis, so the torque is calculated with respect to the selected axis. If you have a net side-ways force on an object, and you move the relative coordinate system further away, causing the torque lever-arm to increase (even moving the coordinate system outside the simulation domain), you can see the torque change because the selected axis is at an increased location w.r.t. the net force on the object.
The force/torque parameters are calculated by default with virtual work method. We calculate the magnetic energy/coenergy in the simulation, and then evaluate the virtual change in co/energy at the surfaces of the selected objects as if the mesh had moved. So, the force calculation is like dW/dx (but for all 3 X,Y,Z directions), and the torque calculation is like dW/dtheta, where theta is the angle of rotation w.r.t. the selected axis.