Carrièrs was a Parisian sculptor and had exhibited portrait busts at the Salon in 1879 and 1881. Carrièrs was one year older than Sargent. The painting, like many he did of friends, shows Sargent at his freest and most expressive.
There is no way the image here shows adequately the thick paint, and the rapid brush strokes of this portrait, but it’s typical of many of Sargent’s paintings which he did of friends in his bravura style.
John Singer Sargent, An Exhibition -- Whitney Museum, NY & The Art Institute of Chicago 1986-1987