Artists, and especially photographers, have always been fascinated by the scandalous "Madame X", one of Sargent's most famous portraits, and the one of which he wrote in a letter when he sold it (c. 1917) to the NY Metropolitan Museum of Art, "probably the best thing I've ever done."
Here is the "original" portrait in a black & white photo, the only
known photograph of the portrait as it was originally displayed, with
Virginie Amelie Gautreau's dress strap hanging off her shoulder. Later, after the Salon of 1884 was over, Sargent took the portrait back to his studio on Boulevard Berthier and scraped away the offending strap, painting it so it was firmly attached to the lady's shoulder. You'll have to read my novel to learn more about the whole backstory! (coming late January 2013)
A few years ago, Nicole Kidman posed for some interesting Vogue photographs in which she was dressed as famous portraits, one of which was, of course, Madame X. Didn't quite get the posture right (imho), and Ms. Kidman looks less serene, more startled and anxious than Amelie Gautreau -- and her right arm isn't nearly as contorted (something that Sargent's subject complained about endlessly!)
And then, just this morning, I came across this delicious new take on Madame X. It's featured on a website of an artist, James Kinser (http://www.jkinser.com/more-muse-a-portrait-of-madame-x/madamex-duo), working with photographer Niki Gangruth, who together deftly and brilliantly explore the "rich, undefined land between genders" in a project they call "Muse". There are several other re-visioned famous portraits (Vermeer, Ingres, Magritte) that are well worth seeing. Again, the pose doesn't exactly duplicate everything, especially that twisted right hand, but I think this one has more of the cool serenity of the original. There was, in fact, a strong undercurrent of "gender-bending" at the end of the 19th century and a little beyond (think Oscar Wilde, Aubrey Beardsley, Toulouse Lautrec); Singer Sargent and the crowd he ran with were kind of on the experimenting edge of this kind of "new world."