The fashions-styled by Ronnie Hart, who often dresses the star for her videos-all pay homage to the signatures of summer style. Carpenter parades around the beach and on a boat! wearing an array of retro, pinup-style bathing suits and dresses. The sum total of my knowledge of polo amounts to one late-night viewing of Pretty Woman key takeaways: wear polka dots, resist "Come on, Dover"ing, steer...