@Friedrich: This form of the Reichskriegsflagge existed, so it's no hybrid shit.
It was together with a small version of the today's German national flag in the left upper corner the Reichskriegsflagge from 1921-1933
Without these extra colours it was the Reichskriegsflagge until 1935.
I think you mean this one?
But you're right, it has nothing to do with the Emperor.