https://youtu.be/pULHYU171nw

The shadow display is a static object that displays 2 different images when illuminated from 2 different, specific angles. The images are low resolution black and white images.

This is created programmatically so you can create your own:

1. Create 2 black and white (not greyscale) images that are EXACTLY 20x20 pixels in size. This is easy to do in MS Paint or similar. It looks best if your images have a white background color.
2. Click "Open In Customizer" button ^
3. Choose the nozzle size of your printer. 0.2mm works best. If you choose 0.4mm the whole print will be quite large.
4. Upload your right and left images with the "Open File" buttons.
5. Click "Create Thing".
6. Open Queue.
7. Wait 5 mins
8. Print the output

For more options download the SCAD file and run it locally. The top of the file has extra variables you can try tweaking.