one thing: your is a pronoun! you're is a conjunction of you are. meaning, that you're a sap is equal to you are a sap, not your a sap.

now, for the topic. those kind of propaganda methods are a mix of asian stereotypes, not just japanese, mainly chinese and japanese. we all know their purposes are to instill fear, nationalism, anger, and to rally people to fight for the freedom of american white people.........and a big issue, to drill up support for the internment camps that were all over the country to capture the local enemy.