Words with two meanings are just one type of shared aspect in their system. The "hunting cakes" joke was an example of using a shared aspect that isn't a word. (And while it didn't wow me on the page, I think it's the type of joke that a talented comic could make much funnier through their delivery.)

I agree that most of the jokes were weak, but they basically have to use one-liners in order to give many quick examples, and nearly all one-liners I meet are bad. That said, I genuinely enjoyed the "step ladder" one.