Posterize a photo or video clip while shooting?

Thanks, Kirk, but the reason I'm wondering is, my 6 years old granddaughter was playing with the camera on her old mini-iPad today, and she was able to see the image on the screen as a normal image and (clicking something) as posterized (quite gorgeous!). I wasn't able to investigate it 'cause she wouldn't let me interfere with her playing with it (...), and back home, when I searched online I found only editing apps.

Ok, but you’re referring to editing an existing file. I’m asking about some kind of a filter that’s functional while operating the camera.