The Look Says More
The funny look on the face of the undergraduate says it all. Imagine doing all within your power to arrive at an answer (even though it is hard for one to clearly state the processes taken to arrive at getting the answers), only for the physics lecturer to say, “it is not about getting an excellent answer. You need to show the proofs of how you arrived there.”
The student would question the whole reasoning of the lecture. For quantum mechanics, the only importance is to get the calculation right and get a good grade. To ask them to understand what they are doing is equal to saying that the course is easy when it isn’t. The student’s face, as shown by the muppet, is that of shock, disbelief, and complete impossibility.