Note to Twelfth Night, 1.5.252-254, "O, such love / Could be but recompensed, though you were crown'd / The nonpareil of beauty!"

Viola is speaking of Orsino's love for Olivia. She says that his love is so strong that Olivia's beauty could only—just barely—repay him, even if she were the most beautiful woman in the world.

It seems that Viola, who loves Orsino, is painfully startled by Olivia's beauty. She sees why Orsino loves Olivia, but she also sees that Olivia is "too proud," and feels that his love is worth more than her proud beauty.

Helena Bonham Carter as Olivia