Realistically, the way to do this is with e-ink (used in many e-readers, basically tiny magnetic beads, white on one side, black on the other, which you spin in place with magnets or electrical currents). Then you tattoo an area with e-ink, and have a device you place against the skin that rewrites the image on the e-ink until the next time you do so. Could even be like a whiteboard, with an “eraser” that flips to white and a magnetic stylus that flips to black, allowing for hand-drawn designs instead of machine-applied ones as an option.