When you change the vertical position of a pivot, you are in effect changing the horizontal distance between the stylus/record and pivot point of a fixed length tonearm, which in turn changes the balance. As we reduce the distance between stylus/record and pivot, the measured force at the stylus tip will be reduced. Any adjustment to the vertical position of the pivot that results in the pivot interface and the stylus/record not being inline will result in a lowered measured force.
This can be easily demonstrated. Hold a 5lb weight 45 degrees away from your body (the weight will be farthest from you body). Do the same at 23 and 67 degrees. Tell me which one feels heavier when the only thing that has change is the distance between you (pivot) and the weight.