No kidding! I remember an interview with Joss about that, and the fact that he wanted Kaylee to be heavier than Jewel was when she auditioned for Firefly. He wanted her to look like a woman who really worked hard, and was a woman. The story was that for the movie Serenity, they didn't have time for her to gain the weight back, and besides, the crew of Serenity (the ship) was supposed to have fallen on hard times.
But I absolutely fell in love with Kaylee in the first episode of Firefly, and thought that she was absolutely gorgeous. And I remember wanting to deck Mal for his comments on Kaylee in "Shindig!" That was the first time I ever got worked up over an episode of a TV series!
Mark
Are you kidding? That was one of the funniest lines in the series! Besides, he bought her the dang dress anyway.