Beautiful postcard issued by Hitler's photographer Heinrich Hoffman, celebrating annexation of Austria into the German Third Reich. It shows outline of Greater Germany (Großdeutschland) with Austria included. The caption says "Ein Volk, Ein Reich, Ein Führer" which means "One Nation, One Empire, One Leader". 
A year later the Reich will grow again with addition of Sudetenland and this will be commemorated with a similar postcard issued by Hoffmann. See it here.