It first starts off with a text saying "Subliminal Messages in The Simpsons" in the Spanish language, then it shows a picture of Superintendent Charlie, Skinner, Lisa and Bart in school for 6 seconds. Then it says "Did you see it? Look closely on Bart's head" in Spanish. Then it shows the same image but with a circle on top of Bart's head for 6 seconds again until Regan MacNeil's face pops up with a scream. Then it ends with a text saying "Poor idiot, you fell for it!" in Spanish. The whole video is in Spanish.
NOTE: The following video contains a screamer.