The history of Rolla was captured in a poem by Musset in 1833. Rolla was the man who had paid for Marion as a courtesan whom he couldn't really afford. 

" . . .Marion was expensive. To pay for one night he had spent everything . . .. Rolla peered with a melancholy eye over the  rooftops, he saw the sun coming up. He moved to the edge of the window. Rolla glanced back to Marie, she was tired and had fallen asleep again ..." 

Gervex had painted the poem. But just like Manet's Olympia this was way too direct, and forced Parisian society to face the realities of  prostitution which was widespread in Paris, along with the issues of female sexuality. The ruffled sheets, the quickly discarded corset and man's top hat, left little doubt the passion that this painting depicted. (Musée des Beaux-Arts de Bordeaux ) 

Some courtesans became quite wealthy, even celebrities in Paris as prostitution was common at all levels.  Everyone knew it, but no one of society would dare discuss it. Clearly, Gervex is romanticizing the poem here. But there was another side to this story. Most woman of prostitution did not reach courtesan status. Even those that did had to navigate the troubled straits of a society in deep denial. In her book "Edouard Manet: rebel in a frock coat," Beth Archer Brombert documents pretty well the appalling conditions that most working class women had to live under. A widowed mother, or an unwed woman, if not under the care of a man of means, was left with no economic opportunities. Paris was bursting from population growth and venereal disease was epidemic, and of course with no real cure yet. Edouard Manet, as did his father before him, would eventually die of complications to syphilis in 1883 -- five years after Gervex's painting -- one year prior to Sargent's "Madame X" 
 
Ultimately it would be the artists that would force the public to face the hypocrisy. For most Parisians, Gervex's Rolla could just of easily been a visual depiction of one of the most popular plays of the time called "Lady of the Camellias" wherein Marguerite Gautier, the beautiful courtesan, and the Armand Duval, the young middle class civil servant (whom couldn't afford her either) are left utterly destroyed.  

In 1878, Gervex submitted three paintings to the  Salon: Portrait d'E. Paz, Portrait of Madame G. (Madame Gervex mère), and this painting of Rolla. The last was refused because it was deemed indecent.  The artist turned around and showed the painting in the window of a furniture store at 41 rue de la Chaussée d'Antin for three months (April 20th thru July 20th).  It attracted crowds of Parisians and was so scandalous that it would make Gervex famous. 

Note: 

Beth Archer Brombert; Edouard Manet : rebel in a frock coat; Boston : Little, Brown, 1996. xxii, 505 p. : ill. ; 24 cm. ISBN:   0316109479