This John Singer Sargent painting is striking, isn't it? It makes me wonder if this started the appeal of the little black dress. Certainly, I think fashion was leaning more toward bigger shapes and more yardage at the time it was painted in 1883. When Madame X was shown at the Paris Salon of 1884 it created a scandal due to the placement of one of the shoulder straps. Originally a strap was slipping off a shoulder and caused enough of a stir for Sargent to repaint the strap firmly on the subject's shoulder.
Some famous beauties portraying Madame X...
And the little video that I found on youtube...
If you're interested in reading a fictional telling of Virginie's story, I am Madame X was an entertaining read. The link is to the author's website who has provided a lot of fantastic background information.