Place it immediately after the reveal, as the first reaction in the edit, then follow it with Oi Meu Chapa for a friendly greeting or You What for a second question, keeping this clip as the opening question that frames both replies.
關於此聲音
A single voice speaks Brazilian Portuguese for about two seconds, asking what is happening and calling the listener mermão, a shortened, affectionate form of meu irmão. The quick, rising delivery sounds puzzled and playful, as if a friend has just stopped to question something odd. The line is Brazilian internet slang that spread through memes and short-form videos as a reaction to unexpected moments.