What that quote promises is, at best, that editors and other publishing gatekeepers will do their best not to hold a writer’s appearance against them, and promises it weakly at that. “We would have paid her the same money if she weighed 500 pounds and was really hard to look at” translates roughly to: “We would not try to offer a fat writer less money for being fat,” which seems an awfully low bar. The effect is a little too self-congratulatory by half. While it’s not a direct comparison, I imagine reading a prospective employer proudly promising not to pay fat employees less money than their thin counterparts: “We promise not to violate the law when compensating people for their work”. It assumes, too, that the reader believes it’s normal or somehow instinctive to want to offer less money to a fat writer (or anyone “hard to look at”). A lot of writers who know that editors and agents think of their bodies as “hard to look at” knew what that sentence means for them and what they can expect in trying to get published.