Below is 反省ザル (monkey reflecting on his conduct). I had reason to use the same pose today, when I forgot to bring my textbook to class. "反省！(Regret!)" I said dramatically, just as in the commercial.
This monkey, Jiro, was apparently all the rage back in 1991, and even performed in the US. I discovered him because of Trick. The show had Yamada do the pose in season one and it tickled me though I didn't know what she was doing; I didn't find out what it was called until I read the novelization. I really recommend it for Trick fans that want to learn Japanese and enjoy the best J-drama on a whole new level!
You can buy the same book by clicking the above link. Used copies are usually only 1 yen.
Obligatory YouTube video for Trick-curious here.