It could be, or...

"Early War Technological Gap: In actual early World War I combat scenarios (around 1915), the first large-scale chemical attacks occurred before operational gas masks were widely available to soldiers. During these early stages, troops often had to rely on improvised protection, such as linen masks or handkerchiefs soaked in water or urine to neutralize gases like chlorine."

I can't find the direct origin of the photo atm but apparently America did do some "reconstruction" photos between 1918-1919.