Well, OK, I guess the Facetouch app wasn't specifically created to tease siblings. But Sabrina's been putting it to good use on Max, as you can see.
She was cackling to herself throughout a recent car ride as she hunched over the iPad, and when she finished her masterpiece she showed it to Max and said, in that special sing-songy voice she saves for him, "Looooook, Max! It's yooooooou!"
Max cracked up.
Not to be outdone, Max got the app on his iPad and....
This is eminently more entertaining than when they pull each other's hair.