"The Man in the Picture" by Susan Hill

I really enjoyed this creepy little story. I think it would lend itself well to a creepy little movie, which is not surprising as Susan Hill also wrote The Woman in Black. 

I probably should have read this on a dark and stormy night instead of in the thin sunlight of Thanksgiving Day, but it was still plenty of fun to read about a haunted painting and the story of revenge behind it. The writing was very atmospheric even without help from my surroundings. 

I find myself with two big questions after reading, and I'm not sure whether they are plot holes or intentional ambiguities. Why didn't Mr Parmitter appear in the picture? And what did Clarissa have against Oliver? (I can satisfy myself with explanations for my second question, but not for my first.)