Hi, that is certainly a very striking design for the B.L. Nairn, It is somewhat similar to the Sir William Wallace, which crossed the Forth, with twin side loading ramps for cars but there the similarity ends as the B.L. Nairn appears to have a large passenger saloon to the rear.
An interesting looking ship which I'd not come across before. It took quite a while to find the photo from your link but it was worth looking for.
cheers
Jim