>>46179944It's from a flashback sequence in Origins that shows silhouettes of a young Giovanni and Charmander.
They did it to draw parallels between Red and Giovanni to show that he wasn't always bad. Functionally, it was supposed to justify Giovanni realizing the error of his ways out of nowhere, but in practice, it just seems like more Charizard-wank.
He never actually acknowledges Charizard, and the entire flashback is just a trace-edit of Red and Charmander from the first episode.