Gunnar Andreassen just alerted me on this photo available from Corbis:
Original caption: Thousands of people in all parts of the world laugh and enjoy the antics of Mickey Mouse, the star of stars, but few know the painstaking and intricate work necessary in the making of the popular film. Scores of artists and sound experts work in the Mickey Mouse Studio just outside of Los Angeles, making thousands of drawings and sound accompaniments under the direction of Walt Disney, creator of Mickey. Here is Floyd Gottfredson, one of the artists, making a drawing of Mickey at the studio.
Image: © Bettmann/CORBIS
Collection: Bettmann Standard RM
Date Photographed: February 21, 1933