Short Answer 
Dramatic irony in Ibsen’s narrative enhances tension by revealing secrets to the audience that Nora is unaware of, particularly regarding her identity. Nora’s misconceptions create suspense and deepen emotional investment, as viewers are keenly aware of her misunderstandings and eagerly anticipate her eventual realizations.
Understanding Dramatic Irony
In this context, dramatic irony occurs when the audience possesses knowledge that a character, in this case, Nora, does not. This technique enriches the narrative by creating a tension-filled atmosphere, as viewers are privy to secrets or situations that characters remain unaware of.
Building Suspense through Character Misunderstanding
Ibsen effectively uses Nora’s misconceptions about her past to create suspense. While she believes to have had multiple maternal figures, the audience is aware that her relationship with the nurse is unique and central to her identity. This discrepancy in understanding elevates the emotional stakes of the story.
Heightening Engagement and Emotional Investment
The contrast between what Nora thinks and what the audience knows enhances their emotional connection to the narrative. As the audience observes Nora’s actions, which are based on her incomplete understanding, they become more invested in her journey and the eventual truths she will come to face.