I found a US recruitment poster where in the background you can see the silhouet of the destroyed Ypres cloth hall. The gorilla is holding a log saying 'Kultur'.
What struck me was the King Kong-ish appearance the poster had. And this an odd 15 years before RKO's King Kong first hit movie screens back in 1933!
So this a very interesting reference to a poster which would have been found all over the US and a generation would have identified how awesomely horrid this King Kong must be. So a very clever use of images which can spark a sign of recognition.