It looks like whatever media you put into your playlist. there's no interface for it or anything, you just edit the .ini and when it runs it plays the playlist.
Meanwhile, I've verified that it works as intended inside Hyperspin itself, but as soon as you go into an emulator, things get broken. In my SNES emu: works as intended except that game audio does not get muted. In Playstation 1 and PSP emu: Screensaver does not detect any button presses on gamepad and launches after set time, regardless of what you're doing. Must use mouse or keyboard to exit. Mame: Screensaver pops up behind the emu, so you can't see it, but you can hear it.
Unfortunately, the PS1/PSP issue is a dealbreaker. I'd still use this if it could be made to toggle itself off when an emulator starts up, (or if it could toggle the delay time to infinite when an emu launches, then back to user setting when returning to hyperspin).
I'm sad, this thing is so *almost* awesome...