Shta is a Russian colloquial form of what, and stretching it into shtaaaa turns a simple question into an exaggerated cry of disbelief. The elongated spelling and delivery became a familiar shorthand in Russian-language memes, reaction videos and streams, where the humour comes from hearing a single word carry the whole reaction. Because the emotion is clear from tone alone, the clip travels well beyond Russian-speaking audiences, and creators keep reusing it whenever a moment needs instant, over-the-top surprise without any explanation.