Caricature of the artist (Henry Oulevay)
from the MET site: "This arresting picture was made after Gérôme returned to Paris from a twelve-week journey to the Near East in 1868. He was at the height of his career when he dressed a model in his studio with garments and accessories he had acquired abroad. The artist’s Turkish title for this picture—which translates as "headless"—evokes the poorly paid auxiliary soldiers who fought ferociously for plunder under Ottoman leadership, although it is difficult to imagine this man charging into battle wearing such an exquisite silk tunic. Gérôme’s virtuosic treatment of textures provides a sumptuous counterpoint to the figure’s dignified bearing."
I was about to say it's a large piece so plenty of room to add detail... but it's actually only 31 3/4 x 26 in. (80.6 x 66 cm). So just a lot of time and small brushwork!
That's incredible