Umm....As quoted from Wikipedia
"Electronic paper technologies have a very low refresh rate compared to other low-power display technologies, such as LCD. This prevents producers from implementing sophisticated interactive applications (using fast moving menus, mouse pointers or scrolling) like those which are possible on mobile devices. An example of this limit is that a document cannot be smoothly zoomed without either extreme blurring during the transition or a very slow zoom.
An e-ink screen showing the "ghost" of a prior image
Another limit is that a shadow of an image may be visible after refreshing parts of the screen. Such shadows are termed "ghost images", and the effect is termed "ghosting". This effect is reminiscent of screen burn-in but, unlike it, is solved after the screen is refreshed several times. Turning every pixel white, then black, then white, helps normalize the contrast of the pixels. This is why several devices with this technology "flash" the entire screen white and black when loading a new image.
Electronic paper is still a topic in the R&D community and remains under development for manufacturability, marketability, and reliability considerations."