ɹǝpun uʍop ʞǝǝƃ
From the rules:
Warehouse Elves wrote:
If a player’s Elf Truck bumps into their opponent’s Elf Truck, not only does the moving player’s Truck spin to face the other way, they may also take from the other player’s Truck any toy that they do not already have in their own. The Elf Truck that was bumped into does not change direction or move.
So this means that if the red player bumps into the green player, red gets to take one of the toys from green's truck. Red then turns 180 degrees to face the other way. Green says bad words.