Eyes Shut
If you haven’t noticed, Forrest had his eyes closed in every single photo taken of him in the movie. While this may seem like a tiny, easily-missed detail, it’s no coincidence as the photos were all meant to have Forrest with his eyes closed.
Tom Hanks said that the pictures with the eyes closed were done on purpose as part of his character. Forrest was so busy focusing on making sure that he stood up straight and looked normal in photos, that he always timed his blink wrong.