During the making of the film Lifeboat in 1944, Mary Anderson asked Alfred Hitchcock (1899-1980) what he thought her 'best side' for photpography was. Hitchcock replied:
"My dear, you're sitting on it."
William Bendix and Mary Anderson in a scene from Lifeboat.
The fat man in the newspaper ad is Hitchcock, making his traditional early cameo as he did in all his films (done early so that audiences did not get distracted from the movie).