I'm afraid it goes deeper than that. For example, you could decide to move some functionality from a sidebar to a context menu. this implies reprogramming the

I'm afraid it goes deeper than that. For example, you could decide to move some functionality from a sidebar to a context menu. this implies reprogramming the interface very differently; a skin can't do that. This also implies prototyping a lot. So basically the designer and the coder have to sit together quite a lot, that's not easy when you communicate via internet.