This photograph was on Facebook World War One site.
A French army machine gun team manning a St Etienne Model 1907 machine gun. The white kepi covers suggests the team is taking part in manoeuvres.
This was the standard mg issued to French army units, although in very small numbers, at the start of the Great War.
Photo 2 and 3 show the mg. The middle photo is another mg team in action during manoeuvres. These pictures are from "The French Army in the First World War" Volume 1, by Laurent Mirouze and Stephane Dekerle, an extremely good and useful book that I use a lot, one of my best purchases, actually a Christmas present from my partner.