This sound comes from the voting motif in Squid Game, the South Korean survival drama series that premiered in 2021. Online, creators began isolating the O and X vote button moments for short edits, reaction clips and parody polls. The O version stuck because it clearly reads as a yes or continue choice, even without extra context. It is still used in memes and game videos whenever someone wants a quick TV-style approval cue or a dramatic decision sound.