Pictures showing a character (animals are fine too) with a very beautiful heart-warming smile.
The smiler must express either calm or joy, and always feel comfortable. Acceptable characteristics include relaxed eyes, blushing cheeks, and body language. Paying attention to the viewer or something else that causes the relevant emotions for whatever reason is a great bonus.
Bonus points if the character in question is not known for being very expressive, let alone cheerful.
