Final answer:
The irony in the portrayal of the Nun in 'Canterbury Tales' stems from her courtly, refined behavior and concern for appearance, contrasting with the expected humility and devotion of her religious role.
Step-by-step explanation:
Explaining the irony in the portrayal of the Nun in Chaucer's Canterbury Tales involves examining the contrast between the Nun's religious role and her behaviors and attributes as described by the author. Chaucer employs irony by presenting the Nun as overly concerned with her appearance and manners, behaviors that seem inconsistent with humble religious devotion. The Nun's obsession with courtly love ideals, such as her tender feelings for animals and her refined eating habits, suggest a pretense of nobility that contradicts the expected simplicity and self-denial typical of a nun committed to spiritual service. This ironic portrayal critiques the religious hypocrisy where clergy fail to live up to the ideals they profess.
Overall, the Nun's character is an example of the broader theme in the Canterbury Tales where characters often wear "masks" to present themselves in a light contrary to their true nature or intentions, as seen in the general prologue and various tales throughout the work. This underlying irony serves to highlight the discrepancies between appearance and reality in the social and spiritual fabric of the time.