The phrase comes from Russian streaming culture around streamer Bratishkin, also known as Bratishkinoff, whose live reactions are frequently clipped by viewers. In Russian, the line is a crude, incredulous question roughly meaning what is he doing, which is why it travels well even without translation. Short clips like this are shared on soundboards and in chat edits, reused whenever a streamer, teammate or character does something baffling. Its popularity rests on the instantly recognisable tone rather than context, so it keeps working as a standalone reaction.