O - The letter "o" is pictured by seeing a pair of O-brand overalls with a large letter "O" stitched on them as their logo or trademark. This is a made up brand of overalls, but it works. You can see them above. Sometimes Dr. Memory™ just uses overalls. There is nothing else that needs to be associated with this picture, since the Spanish letter "o" always makes the long "o" sound as in overalls. There will never be any controversy with this letter. That is the only sound the letter "o" ever makes in Spanish.