I'll see if I can track down a photo of the cabin; the cabin is the same as the other standard balcony cabins; it's the balcony that is larger.
Good point about the "sound of the sea"; yes, D734 is at the back of the ship facing aft. And yes, you will hear the sound of the "churn" or the wake if you balcony door is open. Most people LOVE that sound; if you'll notice, most of the suites are at the back. But not everybody favors that lovely sound. If you think you would prefer quiet you should consider a cabin on the side, although you will hear some sound of the sea on every balcony.