I'll explain the joke:

Once there was an Austrian painter that was rather crap so he decided to conquer Europe and kill all the jews, wich makes perfect sense if you're a rather crap Austrian painter but not if you have full command over you mental abillities, and his spoken language was German.

Now said person used to sport a small moustache, remarkably simular to the one in my avatar and he used to belt out catchphrases in German at rallies and so on.

One of the more famous ones (amongst classics like: "Hans wo ist mein bratwurst?" and "Eva du blote zou, ich hat gesacht nur cola light!") was:

"Ein volk, ein reich, ein fuhrer!"

Wich roughly translated means:

"One peoples/race, one empire, one leader/ruler!"