To avoid accidental multi-picking, the front edge of the gripper is always aligned with the rear edge of the (last) product being picked. This is especially important when boxes are smaller than the gripper. In this case the gripper is not aligned centered above the box, which is a common misunderstanding when using Pally for the first time.
Since Pally version 3.2 it is possible to deactivate the edge alignment feature by setting rf_gripper_align_to_edges = False