My guess is that this photo dates back to Milt's days on Snow White or Pinocchio, perhaps even earlier. We all know that he showed tremendous skills from the day he started animating at Disney. After a few scenes with Mickey Mouse in the 1936 short film Mickey's Circus, his career took off into the stratosphere.
Yesterday was his birthday. Milt died in 1987.
Here are clean up key drawings from one of his scenes with Brer Fox from Song of the South. The fox is holding Brer Rabbit and threatens to kill him. "I spect I'll have to skin ya!" What is brilliant here is to see how Milt handled the second part of the dialogue. The fox talks through his teeth, which adds a great sense of menace (as well as comedy).
And look at the first page of the scene's exposure sheet! Milt felt compelled to add a doodle showing how he himself felt about the scene. Hilarious!