The analogy wasn't really about hot dogs and hamburgers, but about complementarity.

Assume that you have something that has a complementary relationship with something I have, but doesn't have a complementary relationship with anything you have. Assume that I'm in the same situation in relation to you. If we trade objects, we both benefit. Hot dog buns and hamburger buns are designed to be complements of certain respective forms of ground meats, hence the naming scheme.

> the perceived increase in value is purely aesthetic

Aesthetic value is still value. Most people would prefer not to eat Nutraloaf three meals a day.

Eating a hamburger in a hot dog bun would be messier than eating a hot dog in a hamburger bun, so the person with the hamburger and hot dog bun has a stronger incentive to trade.