It explains the jew mindset. They want to replace White people with niggers (in movies or otherwise) because they hate Whites. When the reverse is said, her imitated assumption is hatred of Jews (and not mocking what she said) because she's projecting her psychology onto him. For example, niggers are always on the look out for someone trying to steal from them. This is largely because given the chance, they would steal from someone else. It's some sort of normalcy bias where people make assumptions about other people based on their thinking.