This is a visual effect, which Jolin taught in the variety show just released. Probably, you share two wrists, one of which turns first, and when you turn, the inner wrist becomes next to the other wrist, and the back wrist becomes next to it. You turn in your own direction, become the outer wrist when you go down, become the inner wrist when you come up, and the other turns with you. In fact, she didn't turn around, and there was a visual effect again and again.