@JamesIsAmazing I would suggest you re-read the Q&A answer to which you linked in your question. If you read it a bit more carefully, you will see that your current understanding is exactly opposite of what was actually given as the answer.
I will grant you that the question and the labeling of the illustrations seem to be intentionally confusing. The picture on the left is the one that is the right circular cylinder rather than the one on the left. Answer A refers to the second illustration and answer B refers to the first illustration. It is with that in mind that you will see that your original assumption is completely wrong and that is why the “robot” you illustrated would be out of size based on the expansion rule.