This lecture introduces the pink or purple mode, where Thymio uses touch sensors to interact with the environment, allowing it to move forward, backward, accelerate, and turn. It also explores the light blue mode, where Thymio uses bottom sensors to differentiate between light and dark surfaces, enabling it to rotate or follow a track. A comparison is made between a Thymio in pink mode, which lacks environmental perception, and a Thymio in yellow mode, which demonstrates a sensorimotor loop by perceiving objects and adjusting its actions accordingly.