answer:Mac’s Automator should have the functionality for you to knock this out. In short, you basically want to: – launch the Automator on your Mac, – create a new Workflow, – add Action that allows you to specify input folder and filetype, – add Action where it automatically picks file at random, – show you a Preview of the image, to be sure you like it. Or you could possibly write a shell script to do the same thing even faster. Depends on your proclivities. — This guy did something similar, but I haven’t pulled apart his DMGs to look at the detail. Hence, cannot recommend it. But maybe it’ll help.