The clip comes from the French word atroce, meaning atrocious, stretched online into atroceeeee for comic effect. The existing caption sums up its tone as completely atrociously atrocious, which captures how French speaking users share it as a hyperbolic insult for anything unpleasant. Short reaction clips like this spread through soundboards and short form edits because the meaning survives translation, the drawn out ending is easy to recognise, and it can be dropped over almost any fail, flop or disgusting moment without extra context.