Code requirements for adhering wall light to electrical box - does the light need to be attached to the box?
Actually, the code requires larger (heavier than 50 lbs) fixtures to be mounted separate from the junction box. This one is not that heavy but as long as the wires are not exposed it should pass inspection.

The key here though is to discuss it with your local inspector ahead of time if it will have to pass an inspection. This will save you much time and grief.

I think it looks pretty cool but I am not your inspector. 

Good,luck!