The phrase itself is everyday Thai, a blunt informal way of asking who someone is, with the final particle adding a rough, challenging tone. As a soundboard clip, it is used mainly as a reaction sound in unrelated edits, which helps explain why it works in so many different contexts. Its brevity is part of its appeal: at under a second long, it can punctuate a reveal, a cameo or an awkward entrance without interrupting the flow of a video.