How does one do this?

[Akira88x]

http://www.youtube.com/watch?v=ycuf8BVQdZ4

The effect takes place around 0:20-0:22. It's like a flickering effect.
Much appreciated if someone can help me

[NS]

You should Just have a bunch of small clips quickly fade out, but have them start at increasingly larger opacity values. Should give you that sort of gradual flash to the new scene.