Ah, the original post has lost its picture. Perhaps it was this one - http://www.allworldwars.com/image/054/FirstWarlWarMagazines105.jpg. Die Beute in der Marneschlacht: Unser feldgrauen tun siche an einem erbeuteten Proviantzug gutlich - as near as I can make out, something resembling "The booty of the Battle of the Marne: Our field-greys declare a friendly settlement on a captured convoy." And yes, those would be barrels of vin ordinaire those lads are decanting into mugs, mess tins and canteens.
Ah, Beute again! The finding of Allied food supplies and alcoholics by the German troops caused a severe delay. Discipline was hard to maintain, these men hadn't proper food for a long time and they just got after it as they went after the drinks, instead of continuing the fight.
The same happened in March 1918 - coming across our lovely British grub (blimey, things must have been bad for the Germans to find corned beef sarnies a delicacy), and in plentiful quantities, they understandably stuffed their faces