The lines of a modern cruise ship are quite different than those of the classic transatlantic vessles such as the Norway or the United States. The bows of these huge new ships do tend to be somewhat stubby and are easily distinguished from the traditional elongated bow.
The new Queen Mary II has more classic lines than the typical modern cruise ship.
There are tremendous differences below the waterline, as well, with the large floating resorts having much flatter keels than the classic ships. Stabilizers are added to compensate for the different keel design.
The differences are due to the nature of the ships - they are broad in the beam and are not really designed for dealing with regular transatlantic passages. They are more suited to sailing in the calmer waters of the Caribbean and other cruise destinations.
I think if I were doing a crossing, I would rather be on the QM2 than on a "typical" modern cruise ship.