Thank you very much. I left out a last sentence on the same theme.

1) The portrait stands for the dark side of his personality, which he tries to forget by locking it in a room. The moral of the novel is that every excess must be punished and reality cannot be escaped.
2) When Dorian destroys the picture, he cannot avoid the punishment for all his sins, that is, death.
3) The corrupting picture could be seen as a symbol of the immorality and bad conscience of the Victorian middle class.
4) Dorian and his pure, innocent appearance are symbols of bourgeois hypocrisy.
5) Finally, the picture, restored to its original beauty, illustrated Wilde’s theory concerning (ON, ABOUT) the eternity of art.

1 answer

1 - 4 -- OK

5. delete "concerning" and replace with "about"