Also called foo gas, like you say almost all ways a one shot remote mine, soviets used a lot of these on the defenses of Stalingrad, they were most effective when used in gullies or other terrain where the flame was confined to the target area. Americans used them in Korea, the British home guard set up thousands of them after Dunkirk, and Germans used a few in Normandy called hedge hoppers that were designed for the blast to carry them over a hedge and then burst into flame. The one in the picture looks like a field modification of an industrial fire extinguisher to me. It could be a hose coming out the back for fuel, but I think it's more likely just to be a pole to brace it when fired.