Miss Tita Burning the Letters (Situational Irony)
The narrator greatly underestimates Miss Tita, and believes that because he is kind to her and she is naive, she will help him get the letters so long as he makes her feel less lonely. He treats her rudely after she implies that she wishes him to marry her, and still fails to see that she is capable of more drastic action. When she burns the letters, the irony of the narrator's oversight is revealed; Miss Tita asserts her power and agency over the objects that he so desperately wanted.
"My idea was still to exclude brutal solutions" (Dramatic Irony)
Although the narrator, at the end of the novella, says he does not wish to resort to "brutal" methods of obtaining the letters, the irony is that his intrusion into the home of the Bordereaus has already been brutal and violent. The shock he brought Juliana most likely killed her, and he has caused immense suffering for both Juliana and Miss Tita. His blithe inability, or unwillingness, to recognize this fact which seems obvious to the reader constitutes dramatic irony.
"Did she think I had made love to her, even to get the papers? I had not, I had not; I repeated that over to myself for an hour, for two hours, till I was wearied if not convinced." (Dramatic Irony)
As the narrator experiences shock over Miss Tita's suggestion that he should marry her, he explains that he never made an attempt to imply he loved her or insinuate romantic affection. He repeats this over and over, as if to convince himself, but the reader knows—as they have read the entire narrative that precedes this moment—that the narrator, in many instances, did insinuate that he was romantically interested in Miss Tita, taking her out on gondola rides and convincing her that he was buying flowers in the garden for her.
“What a striking face! Do tell me who it is.” (Dramatic Irony)
After Juliana shows the narrator the portrait of Aspern, he pretends not to know who it is, which is ironic given his extreme obsession with Aspern. Although he tells Juliana that he doesn't know who it is, the reader is well aware that the narrator immediately recognizes Aspern's likeness.
