Trading would imply that Swimmer963 is giving up some of her attractiveness in exchange for attention, by treating 'beauty' as a resource that can be depleted. However, her attractiveness in your example of the trade (beauty attention) isn't depleted significantly.

Perhaps you meant something like trading her spatio-temporal presence (in which the subject gets to admire her visage in a non-awkward social situation for a prolonged period of time) in exchange for the subject's attention; or more succinctly, trading face time with attention?

I agree with you that some advantages can indeed be comparative advantages, but beauty (in this context) is simply an advantage.