The textures from these can still be seen on the discs, and I have posted them earlier in the texture rips. Obviously, this would be an alpha version. =0) He seems to have used the textures to recreate the buildings in Milkshape.
Nothing really significant about it, it's just something cool to look at. Some people (I know I'm one of them) are usually really interested in what games looked like before they went gold. Sometimes a pre-alpha version might look similar to a gold copy, other times it's like two completely different games.