I first learned of Marion Davies when I saw the HBO movie "RKO 281", about William Randolph Hearst's attempts to stop "Citizen Kane" from getting released (Melanie Griffith played Davies). I've finally seen her in her first talkie. Robert Z. Leonard's "Marianne" is nothing special on its own, depicting a US platoon coming to a small town in France during World War I. A lot of the humor derives from the troops' arousal at the sight of the title character, played by Davies. Since this got made before the Hays Code, there's one line that I'm sure couldn't have gotten included just a few years later (you'll know it when you hear it).
I understand that Davies was usually a comedienne. I haven't seen most of her work, so I can't judge how much this movie uses her talent. Sometimes I get the feeling that she mainly got put onscreen for her looks (she WAS a real babe).
All in all, the movie's nothing spectacular. I guess that it wasn't intended to be laugh-out-loud funny like the Marx Brothers. Worth seeing, if only once.