Sunset and Trees

This photo's rather intriguing, Love the limited pallet used and the softness of the overall shot, but at the same time it leaves me wondering was the motion blur on the trees (looks to be lens shake actually) purposeful? Or did it just happen? I've tried to do purposeful cam shake shots and they never turn out the way id like them to, but when there accidental and candid ala this (old account here) [link] it just looks so much different.

Either way i love how the shot congrats