No, I'd argue it isn't. Even if you connect an external keyboard an display to the iPad, you are just getting the ipad experience on a larger screen. There is never any transformation of interface when used this way. Apple has never allowed mouse/trackpad on iOS(with some very very narrow exceptions) so it's not transformative - you are still getting the same experience essentialy.

For it to work on the iPhone, they would have to add support for some kind of mouse/trackpad, because the iphone itself is sitting in the dock - and I don't see apple doing that in a million years.