Drag the Fidget Spinner to spin it. However, you have to drag it from the top, and spin it to the right. Sometimes it looks like it's spinning slowly, but it's really spinning so fast that the frame rate is off.
The reason this was so hard is because Scratch can't measure the speed of the mouse very well, so I had to improvise. As soon as your mouse is down, then it starts a timer. Once the mouse is off again, it stops the timer. It then calculates how much the direction has changed, then spins depending on that number and the time it took to spin it. It slowly slows down while spinning.