The "story's attitude" is usually a reflection of the narrator's attitude, which is correctly called the tone of the story. First though, there are several interesting sources of attitude toward the religious relic, the Prophet's hair. The first is Hashim. He is a deceitful and hypocritical man, so when he expresses his attitude as being one of disinterest in the relic's religious value, we have no way to know if he is reliable or not. On one hand, he is greedy and the relic's setting is beautiful and of value. On the other hand, he immediately requires of his family that they read the Quran two hours daily and burns all other books in his library and insists on prayers five times daily. His children have attitudes of loathing and dread toward the relic. They each seek to hire a thief to take it. Huma even calls her family "the hair's victims."
The narrator's attitude, reveled in the tone, is an ironically sarcastic one. It seems the narrator's attitude is devoid of awe or fear of the relic itself, speaking of it in words with a humorous undertone. This undertone is exemplified by high diction (i.e., elaborate vocabulary and syntax) and by words that demonstrate a suggestion of disdain or exaggeration, as in this passage:
The thieves--no doubt alarmed by the pandemonium, by the procession through the streets of the endless undulating crocodiles of lamentation, by the riots, ... the massive police search ...had evidently panicked and hurled the phial into the gelatin bosom of the lake.
The vocabulary is sophisticated (e.g., procession, undulating, lamentation), the syntax elaborate, words and phrases reveal a hint of disdain or exaggeration: e.g., endless undulating crocodiles, pandemonium, gelatin bosom of the lake. All in all, it seems safe to say the "story's attitude," or narrator's tone, is ironic sarcasm suggesting a lack of deep felt respect.