It's been pointed out many times over the years that Duffy's style is reminiscent of Bridgette Bardot during the 60s. Angele, and a few others in the shoubox, said the Well Well Well shoot was directly inspired by Bardot's style in the movie Le Mepris (1963) and Viva Maria (1965).
Felipe provided the first comparison image and I did the rest. More are welcome. Just put the photo of Bardot and the photo of Duffy together on one image, upload to imageshack.us (or anywhere) and leave the link in the shoutbox.
Scroll to 2:39 and compare this with Duffy's Well, Well, Well video (thanks to DM for the link):
I was also thinking the same thing and found this picture:
Compare with Duffy's Well, Well, Well video: