I read the article, cool horizons ! The abstraction I still can't figure out is the complexity of "client side" interface modelization. If our toaster is toasting ... no one should nor could toast anything. But what if the "client side" interface don't consider this state ? I understand the fact that a toaster, depending on the space, can be a icon, a sounds a color or an hologram but what if toaster can't control its look'n feel and that the look'n feel is not compliant ?