On second thought's pulling out such a watch as shown before, is kind of technically impossible. Considering the whole thing's flexible, where do the put in the circuit board and components like chips, batteries etc ? That is a concept render, but i dont think the hardware technology today will allow for such a design.
In that youtube video you'll notice the actual hardware powering those flexible screens are a giant sized block below the flexible display, which they hold on.
So yeah we aren't technologically there yet.. Or atleast Samsung isn't. Who know's maybe Apple will figure it out.