Why does the dialog the narrator overhears at the bazaar trigger the climax and the final insight of the story "Araby"?
Having had to wait on his inebriated uncle, the boy of Joyce's "Araby" arrives too late at the bazaar and finds it to be much less than he has anticipated, as earlier when he has reflected,
[T]he syllables of the word Araby were called to me through the silence in which my soul luxuriated and cast an Eastern enchantment over me.
Instead, most of the stalls are closed and much of the large hall is in darkness. Remembering that he has come to buy a gift for Mangan's sister, the narrator moves toward a stall where he overhears a young English lady and two young Englishmen--there is "no Eastern enchantment" to them--speaking of mere trivialities. After she inquires if he wishes to buy anything, she resumes her mundane conversation with the young gentlemen.
The spell of the exotic is broken; the narrator drops two pennies against the sixpence in his pocket in a symbolic gesture of the pettiness of the scene around him. In his disillusionment, he departs in the darkness of the hall that symbolizes for him the darkness of his foolish imaginings,
I saw myself as a creature driven and derided by vanity; and my eyes burned with anguish and anger.
Unlike "Araby," the bazaar is a cheap imitation where mere trinkets are sold. But, like the Irish romantic poet James Clarence Mangan who wrote of doomed love and despair, the image of Mangan's sister in her brown dress and "silver bracelets" now conjures no "grail," but instead suggests someone tawdry who effects the narrator's despairing insight.