Great use for live photos - have my girl completely clothed in the beginning of the shot and transition quickly to her fully nude. One long press away on my screen from the goods and everyone else is none the wiser to it!
Not interested in doing specifically what you mentioned, but I do wonder how you did it? Does she just quickly rip her clothes off or can you edit these videos that are associated with the photo and have them still work as a live photo? I also wonder if it's possible to pair a higher FPS and/or higher resolution video to the photo, much like the live wallpapers that are higher quality, and use that and have it work?
Apple really needs to let developers make apps that can add custom live wallpapers. Dynamic wallpapers too! It has been a couple years and we still have the same colored circles. I think that could be a big market on the App Store. There should also be a setting to autoplay a live photo when you press the lock button (since Touch ID is too fast to see the lock screen now).