This is a major cutscene, and it introduces the concept of Rings, which can make things movable.
The Student jumps across a gap and finds something weird. There is a yellow ring stuck on one of the boxes, and when she jumps on it, the Box bounces upwards, and the Student keeps hopping on it, implying that the Box is movable.
Before long, she slips down and holds onto the ring before she falls into the space. When she climbs back up, she kicks onto another Box, and the Box with the ring is now hovering in the air.
This also marks the start of the first box-pushing challenge in the Bridge Building minigame.