Finally he came back, went over to the picture, and examined it. In the dim arrested light that struggled through the cream-coloured silk blinds, the face appeared to him to be a little changed. The expression looked different. One would have said that there was a touch of cruelty in the mouth. It was certainly strange.
– Oscar Wilde
The Picture of Dorian Gray, Chapter 7. Following his brutal dismissal of Sibyl, Dorian examines his portait and is startled by a change in it: in the mouth there is an expression of cruelty. The portrait has become a moral metaphor of Dorian. As his soul embraces evil and corruption, so the painting will bear the burden of his growing ugliness. It has taken on a life of its own and will become both Dorian’s curse and his doppelganger. What started out seemingly as a novel of manners becomes a true Gothic novel.