This film was released in 1938, the same year Nazi Germany annexed Austria into their governance and just prior to the start of World War II.
When the Austrian dancing is being showcased in the beer hall, a young boy (appears to be about 8 or 9 years old) walks by carrying a liter stein full of beer. Though European cultures are much more liberal with respect to youngsters and alcohol, that's a significant volume of beer for a lad. (Hopefully, he was fetching it for one of his parents.)