The line comes from the closing sequence of Looney Tunes cartoons, where Porky Pig traditionally bids the audience farewell with 'That's all, folks!' In Spanish-language broadcasts, that farewell became 'Eso es todo, amigos,' and generations of viewers heard it at the end of dubbed episodes on television. As clips moved online, the short sign-off was lifted for video endings, reaction edits and soundboards, because it needs no explanation. Its brevity and familiarity keep it useful as a universal way to say a video is over.