A screen saver, for Windows, that fades in and out random overlapping pictures of your choice. It’s intended for large collections of camera-facing faces, hence the name. I’ve had good results with company staff directories - it’s distracting, but it’s the good kind of distracting.
Download, install, and point it at a directory full of images.
The sample screenshot uses faces from public web searches, and this would pair nicely with something that picked a tag and refreshed the local directory every now and then.