when it is made up of E Ink technology. cause the E Ink (like that used in the Kindle) basically only uses power to switch the image on. after that it does not require any power to keep the image the way it is. while currently color E Ink is still some way off, but it is already available in prototypes. i definitely will not have a monitor switched on consuming power all the time as some form of photo frame. but the E Ink is definitely something the manufacturers should think about for photo frames besides eBooks.