I used to breed and show Siamese - I aimed for a specific middle ground: a good profile without much nose break but not the extreme long head, large ears but not batlike, dark eye color, and a svelte but solid body. It was still possible at that time (70s) to show a cat to Champion without the extreme type that wins today. I'll have to find a photo of my old champion HyBrasil Cormac and put it up on the web. He was a good example of a typey but not extreme Siamese, although he was a little large for standard he was a well balanced cat with a beautiful profile.
This is what I would consider the old or applehead type. Particularly the perfectly round head, the relatively small ears, and the eyes quite small in relation to the head size.
This is the most extreme type Siamese (it's actually a colorpoint) that I could find on the net. Ugly, ugly cat in my not so humble opinion.
My little Lilac seems to me to be "typey" - having the long nose and long body of a Siamese, without the extreme type.