Talking about 'Swinging London' of the 1960s, one just cannot miss out Twiggy, the modern muse who redefined the idea of feminine beauty. I am not sure how this appealed to the male sex, but for most of the female sex (perhaps especially the feminists), Twiggy's androgynous style and silhouette as opposed to the often angelic/erotic femininity celebrated by the arts and culture of the preceding centuries was outrageously rebellious and appealing.
Though Twiggy herself expressed that at the time she was not fully aware that she was creating a new style for the world, that being a teenage model she was just acting according to instructions, it is obvious that her phenomenon has carried through to this day. Kate Moss has been hailed the second Twiggy, but personally, I find Agyness Deyn much more the Twiggy spirit. But I guess for most of the male sex today, the female ideal is still the one in the 16th Century.