See link showing what anamorphic installations are. From one angle, it's a bunch of random junk, then you walk to the right viewing spot, it transforms instantly into a clear picture of something. They're incredibly complicated and time consuming but very impressive when completed.
This program would
do all the work for you. It would take the picture you want to create, analyze the dozens or hundreds of random objects you take a pictures of, color, lightness or darkness, size, shape etc, and create a map of where you'd place these objects to create the desired picture.
With a little creativity you could have a lot of fun with this. For instance, your loved one could come home to find the living room strewn with various stuff from the kitchen, cans, bags of noodles, seasonings, then as they walk to one position it spells "Happy Valentines Day Sweetie!" with an image of a valentine heard.