The Bible says it was 450' long and 75' wide. It says nothing about the shape, though. I seriously doubt that it had pointed ends. It just needed to be a big box that would float around with God's guidance. No propulsion or guidance needed. Nobody knows, of course, but my guess would be that it looked more like this.
The ark did look like a shoe box much like what you have here and not like the fairy tale shape this one copies out of children's sunday school books. What a waste of time and money.
I read something about the proportions that God gave for this project. The article stated that a vessel this shape and proportions would be the most stable and seaworthy possible. Basically, it was perfect for the task.
I think it's safe to assume that Noah had knowledge of proper boat construction. And I think it's also safe to assume that God would allow Noah to build a boat that would not be a torturous ride in rough water. For those reasons, I believe the Ark would have resembled a boat more than a box. The box/boat in that drawing would have been a sorry place to spend any time on rough seas - which I would think are pretty likely in such a massive environmental change. As for the shape of the replica in Kentucky.....I'd say it's also a little off.