The Lenovo Yoga Book is quite different in the sense that the multi-screens are never really viewed as a single form. One screen is more of an input device, while the other is what we would usually see as a screen. I'm not saying that the foldable phone can't do this, just that it's very different from a "phone that folds out to have a bigger screen for watching media" device that I've seen people expect these foldable phones to be.