Or as I like to call it, a BFG. (Doom reference there.)
So, supposedly, this ship requires less crew than the Enterprise to operate it. Then, why was the ship built to resemble a ship that needed crew, considering that these ships had equipment specifically built to house and sustain a crew, why not choose a shape that efficiently maximizes the potential of the automation-ness?
I'll take a stab at this. The ship is essentially a roving weapons platform, so it does not need a large crew to do its primary job. However, I can envisage scenarios when transporting a large number of troops for a hostile engagement on some distant planet might make this ship useful as a very powerful (and thus not easily dissuaded) troop ship. Such a ship, whatever its ultimate purpose, clearly represents a major expenditure/consumption of resources and it would only be logical for it to have a secondary function to make that investment more manageable. As such, its shape is conducive to transport duties while maintaining its primary purpose as a roving weapons platform.