The crane has picked up the ball with the magnet and is about to drop it on the labyrinth.
The crane, located at he upper right of the table, can be activated by hitting the block in front of the upside down U magnet 3 times. When the barrier has been struck three times, three green indicators will be lit. The next time the ball goes there, the magnet will pick it up. The crane will lift the ball via the magnet and then bring it over the labyrinth and let go.