A major difference between the render and the (un)finished product is what appears to be a dark glazed blue glass at the base instead of super transparent, light glass. I really liked the transparency at the bottom and top of the design in the render. It helped to lighten the entire composition. What we're seeing here is technically transparent, but it appears a hell of a lot darker, which alters the balance of the tower altogether.
"Then each time Fleetwood would be not so much overcome by remorse as bedazzled at having been shown the secret backlands of wealth, and how sooner or later it depended on some act of murder, seldom limited to once."
Against the Day, Thomas Pynchon