On a denotative level, this is a picture of a battered Nazi Second World War helmet hanging from a bloody baseball bat.
However, the poster holds more detail than first thought of; the typically American baseball bat is plastered in German signatures. This can be interpreted as the Nazis killing their own men, or a humiliating American onslaught.
On a connotative level, the up-side-down German helmet can be a representation of the Germans losing the war. Supposing the baseball bat is American, it infers that the country has more authority over the vulnerable-looking Germany, because the bat doesn't fit in the frame, suggesting it is much bigger and stronger than the enemy.
The negative space in the picture is strategically filled with text, the remaining becomes a visual aspect in itself; It emphasizes the isolation and dullness of which the soldiers experienced.
The poster's content gives a brief outline of the film; "Once upon a time in Nazi occupied France..." Then the picture suggests Americans beating down on Germans.