The apparent difference in the speed of the buggy for different situations can be explained by the relative motion of the viewer and the buggy. If the viewer is stationary and the buggy is moving, the buggy will appear to be moving at a certain speed. However, if the viewer is also moving in the same direction as the buggy, the apparent speed of the buggy will be slower. Similarly, if the viewer is moving in the opposite direction as the buggy, the apparent speed of the buggy will be faster. This is because the relative motion of the viewer and the buggy affects the apparent speed of the buggy.