Robert Leonard was married to actress Mae Murray who was the star of the film. I believe the photo to be from "The Big Little Person" 1919 Universal. Of the five films Rudy made at Universal, in only one did he have a mustache, and that would be this film. He was clean shaven in the other four Universal films "A Society Sensation", "Delicious Little Devil", "All Night" and "Once To Every Woman"
Here is the movie ad with the film un-named
Here is a full photo from "The Big Little Person" 1919 Universal