How does disguise affect viola’s development in the play? (3 main examples)

Viola has been called a central character because of her influence over other characters in the play. Some critics suggest that her disguise as Cesario allows her and the audience to see through the pretenses of characters like Olivia and Orsino. For example, Olivia's reclusive and elaborate period of mourning for her brother stands in contrast to Viola's optimistic and active engagement with the world of Illyria in spite of her own brother's apparent death. Additionally, Viola's patient and self-sacrificing love for Orsino helps the duke to reassess his own artificial and self-indulgent love of love. Viola's observations about the destructive influence of time and melancholy on youth and beauty have been compared to similar remarks made by Feste. In I.v.241-43, for example, she upbraids Olivia for wasting her beauty by leading it to the grave rather than marrying and transmitting her beauty to her children. In II.iv. 110-15, thinking of her own hidden love for Orsino, Viola paints a vivid picture of the effects of time and unrequited, unproclaimed love on the "damask cheek" of a maiden who "sate like Patience on a monument, / Smiling at grief."