The light probe is the one used in the last step of the tutorial, kitchen_probe.float, and the lightprobe is plugged in the ball's Alternate_Diffuse like in the very beginning. Don has the same material, except that his skin textures are plugged in the lightprobe's Surface_Color. Both Don and the ball have pretty much the materials that were used in the tutorial before. The floor has no lighbprobe node, it's just a tiles node plugged into the Ambient_Color (with Ambient_Value set to 1). The pattern comes from a cloud node that's plugged into the tile's colors.