The twist ending is such a trope that it has become almost laughable - and impossible to pull off with credibility; but there is another subtler kind of twist ending that I'm interested in: It happens literally at the last beat of the film and it changes completely the tone of the ending. It isn't necessarily some startling reveal like in Sixth Sense; but something happens to rapidly and drastically shift the audiences feeling about the movie - and then the movie ends - like that.
For example the movie Buried with Ryan Reynolds is like this.
In the last second of the movie our hero undergoes a change of fortune so drastic that it's impossible not to instantly reassess everything. It isn't a twist as such, but it's definitely something.
Does anyone know what this trope is called or have a clear way to distinguish it from the more common version of the twist ending? Upon reflection - much of what differentiates this trope of this from the twist is the pacing - the punch and done feel of it.