Second, count the balls. Assume recycling. Imagine 3 pics. Before stacking (), after stacking (on), and after removal for recycling (). Imagine say 30 balls visible on the hill and in the gully in . After stacking balls on the road this number falls to say 20. Ten balls will be on the road, or more due to addition of balls from off-frame. After recycling, the ten plus road balls will be gone and possibly some additional balls from the gully, so say 15 to 20 balls visible. Compare off to on pics. If the number of balls off the road in the off pic is greater than the number of balls off the road in the on pic, then off is and it is the first picture. If the opposite if true then off is and it is the second pic. If the number is the same then we can’t say anything for sure, but haphazard recycling seems less likely.