This level features a bridge that retracts when you step on a pressure plate. The puzzle piece is on the other side of the gap. To get it, you need to use your shadow. First, walk across the bridge, triggering the pressure plate and causing the bridge to retract. Then, rewind time. Your shadow will now walk across the bridge, and as it steps on the pressure plate, the bridge will retract for your shadow. While your shadow is on the retracting bridge, you can safely walk across the now-extended bridge to reach the puzzle piece. This demonstrates how your shadow can interact with the environment in a way that benefits your current self.
