A commonality of all the boxes on the right is being on the right.
A commonality of all the boxes on the left is being on the left.
There is no offside in golf. The rules of the game only apply if when we are playing the game.
Here, Wittgenstein might have said Bongard problems are another language game and the confusion arises from using words in a peculiar way...the game is pretending there is a problem in a Bongard problem.