Maybe you could use a handheld scanner type device to load the next image and send power to each card, or an electronic Rolodex where you stack the cards and it

Maybe you could use a handheld scanner type device to load the next image and send power to each card, or an electronic Rolodex where you stack the cards and it flips through a set amount reconfiguring them. Both of those ideas would require some hardware development though. I forgot to add: very interesting project and amazing to see the fruition of your efforts!