Marlene Dietrich wrote the story for Blonde Venus and it seems she made an attempt to broaden her exotic appeal. She's still a cabaret singer. And she meets her husband (Herbert Marshall) while she's swimming naked in a lake in Germany... but then the narrative diverts towards a more conventional Hollywood soap with Marlene suffering poverty and disgrace while having to provide for her son alone.
The best (and most famous) scene is a night club number when she passes through the tables in a gorilla costume, only to remove the disguise and sing the excellent 'Hot Voodoo'. But the glamour and the naturalism clash. Dietrich complained the film was damaged by censorship and it's possible to see that her descent into the gutter might have been intended to be more realistically brutal.
Josef von Sternberg wasn't the director for social realism though. When his star is compelled to live in a flophouse, he creates the most beautifully lit flophouse in cinema. The milieu is exotically sleazy. Marlene does a lot more acting than usual rather than being a model for von Sternberg's adoring lens.
There's a pre-stardom Cary Grant as an unlikely gangster. Sidney Toler is good in a cameo as a squalid, shifty detective. It's an unusual film. No one else can walk on the wild side with Marlene's insouciance, but it just doesn't compute when she washes dishes to make ends meet. That's what Lillian Gish does in a Griffith film, not Dietrich in a von Sternberg. It's an interesting digression but only intermittently successful.