and what is the idea?
The idea is (was) to highlight the textures and shapes of the leaves and branches of this tree using sidelighting or backlighting to create a pleasantly aesthetic result.
I cannot exactly speak for Chris' motivations of course but his treatment of the image points to this.
I see in another thread that he has reworked what seems to be the same base image - like this one he hasn't quite got it right.
BTW my personal approach to critiquing images is not to be too harsh and negative but rather to suggest, and lead, and encourage in those situations where an image may not quite work. In this instance my suggestion was to reshoot different compositions with the same broad goal in mind.
I stand by the thoughts in my original post.