My mother had a picture of her granddaughter on her laptop as a wallpaper. I made a hundred copies of this photo and switched the wallpaper to the slide display mode to show the same photo, i.e. files change, but there is no image on the screen. Images change every 10 seconds. On one of the photos, I painted small twisted eyebrows and periodically for 10 seconds my niece appears. Her mom thought she was going crazy, or she had a virus on her computer, but every time she had a moustache and wanted to show it to someone, it disappeared.