As with other Pixar movies, Inside Out 2 had hidden gems—including one for the forthcoming Elio.
https://www.wired.com/story/pixar-put-an-easter-egg-for-its-next-movie-in-inside-out-2/
https://www.wired.com/story/pixar-put-an-easter-egg-for-its-next-movie-in-inside-out-2/