It is true that grasping a apple by a robotic hand is a more specific demonstration, showing greater precision compared to a simple ball, because the apple has less uniform surface and consistency. We can even admit that the Festo Bionic Handling Assistant shows a nice ability to handle irregular shapes and delicate textures. However, this specialization relationship is not a stable hierarchy; it is conditional on the demonstration's objectives. For example, if the goal was to test the reaction speed of the robot to catch a fast-moving object, a red ball, with its predictable trajectory, would be a more relevant and potentially more complex test to master than simply grasping a static apple. The relevance of the specialization depends on the evaluation criteria of the task.