It's during the making.
It's not afterwards.
It's not because of a good review.
It has to do with ideas coming together to somehow make this greater whole where everything becomes clear.
It's quite a strange experience.
I think many artists would say there is a moment when that happens, in whatever medium they're working, and when it is a really good piece of art, it can also give that experience to the viewer.
quote from mike nelson interview in border crossings