You can drag virtually any image file format onto the 3D device in Rotato and see its content on the display immediately. No more fiddling with materials and shaders, it just works, and here's how to do it.
Make sure the size of your imported image matches the device in Rotato. Next to the scene's name, you can click the little 'i' icon and see the size you'll need.
When you save a scene, the image is embedded in the file. No need to distribute the image alongside the .rotato file. To keep the file size small, this is not the case for videos.