My first recommendation is removing any lines that loop around and doesn't contribute to any of the box's shape. I see about three loops you can delete right away.
The lighting you've got going on is pretty cool and the overall scene looks nice. For your portfolio I would add some sort of man made light source coming from the right at an angle so you could get some spec hits off of the detail on the side. Most of your detail facing the camera is in shadow which works for the vfx…