Mine was Simon the monkey, and it's the only reason I have kept him around since now. I forgot what it was for. He's only given me two so far... I think.
Sally, when she moved out she sent it because we were 'Best friends' even though I fought against her liking me as I preferred my other 9 villagers over her. She just insisted we were besties until the end. She even took Diana's place at my birthday party. D:
I only have two pictures. Bianca was the first to give hers to me and then Wart Jr. gave his a few weeks ago. Funny enough, Bianca moved out today and I received a 2nd picture of her in her last letter.