I'd say it's some style, some technique - particularly when compared with the classic Catskill.
1) Tail and wings are generally longer/higher than a classic Catskill;
2) Before the tail is tied in, a thread bump is created in order to spread the fibers and cock them upwards. (A little head cement on the tail at the tie in point helps keep the fibers separated even when wet.
3) The quill body is actually made from two quills and is wrapped in such a way to make a tapered body:
4) The wing is tied on after the body with the butts pointing forward - in order to create an impression of a bigger thorax;
5) The hackle is tied in front of the wing with the first wrap behind the wing going backwards and then forward back to the tie off point. The cross wrapping gives a bigger spread of hackle compared with a classic Catskill:
6) His method of tying in the wings is hard to explain but it actually has its own entry in the Benchside Reference.