As https://news.ycombinator.com/item?id=42260033 said, the difference is not a new discovery, not surprising, and not the focus of the paper.

Making the 'fundimental difference' the focus seems like laying the foundation to a claim that AI lacks some ability because of the difference. The difference does mean you cannot infer abilities present in one by detecting them in the other. This is the similar to, and as about as profound as, saying that you cannot say that rocks can move fast because of their lack of legs. Which is true, but says nothing about the ability of rocks to move fast by other means.