I call these Easter Egg Lamps but the egg shape could be used for any time of year (the first time I created them was for Easter). Using two to three photos a lithophane lamp can be created and the image shows through when the light sourced is on. If using only two images, both should be landscape, and if using three all three should be portrait.
I can print these out for $30/each and bear in mind it takes 24 hours to print them out!