This is a Slowcide simulation. A slowcide is a trick where you release the stick and let it fly around the diabolo causing some kind of wraps the string. The main goal for this simulation is to introduce to you how slowcides work. Each stick can fly in two directions and either side of the string.

You can experiment freely with how the trick works by pushing buttons above and below the sticks. The image in the center will show you what kind of wrap is currently on the diabolo.