The women's responses to being forced to wear burqas demonstrate their self-image. Mariam doesn't mind wearing the burqa--it provides security for her, especially since she does not view herself as worthy or attractive. The burqa allows her to hide; so psychologically it furthers Mariam's poor self-image and her desire and ability to continue her hiding.
In contrast, Laila has always had positive reactions to her physical appearance, respect from her family members as a female, and a healthy sense of independence. When she is forced to wear a burqa by her abusive husband, she bristles and begins to lose some of her confident, positive self-image.
For Mariam, the burqa is a comfort. It allows her to observe others freely, without fear that she will be exposed to the "scrutinizing eyes of strangers." Since others cannot see her face, Mariam imagines that the "shameful secrets of her past" will not plague her interactions with others. As a harami (or illegitimate child) of a businessman, Mariam has always had an added burden in life. Not only does she have to navigate a fiercely patriarchal culture as a woman, but she must also live with the shame of a heritage she did not choose.
When Rasheed marries Mariam, it is he who orders Mariam to put on a burqa. Until her marriage, she had never worn one before, and her initial reaction to the burqa is not positive.
She practiced walking around her room in it and kept stepping on the hem and stumbling. The loss of peripheral vision was unnerving, and she did not like the suffocating way the pleated cloth kept pressing against her mouth.
However, Rasheed is unconcerned with Mariam's discomfort. He merely asserts that his wife will soon become accustomed to wearing the burqa and may even come to like wearing it. It is clear that, in this instance, Rasheed exhibits no sympathy for Mariam whatsoever. Instead, he is primarily concerned with his image as a husband. To Rasheed, a wife in a burqa demonstrates his control over his household and ensures the preservation of his "nang" and "namoos" (honor and pride). He calls other husbands who allow their wives more freedom, "soft men," and he menacingly warns Mariam against dishonoring him.
In all, Mariam comes to realize that her husband's will is as "imposing and immovable as the Safid-koh mountains looming over Gul Daman." Basically, the burqa represents a psychological burden and a form of oppression to Mariam, one she only manages to free herself from through her sacrificial death.
Laila also experiences a similar psychological scarring from being required to wear the burqa. When the Taliban announces its onerous rules for women, Laila is flabbergasted. According to the new rules, women without burqas will be severely beaten. No woman can leave her home alone; in fact, she must stay in at all times, as a matter of practice. If she is found on the streets alone, she will be beaten and sent home. No woman must wear any form of makeup or jewelry; a woman is not to paint her nails, laugh in public, or make eye contact with men. Above all else, no woman is allowed to work or attend school.
The burqa is only a means for the Taliban to enforce what many Muslim women have never needed to submit to. Laila, as a young and beautiful woman, finds it difficult to resign herself to such draconian rules. However, the burqa provides a measure of privacy. In the story, Laila despises the burqa but realizes that the burqa allows her the comfort of anonymity. Although the burqa obscures her vision and makes it difficult for her to navigate her way on the streets, Laila is thankful that her old acquaintances will never recognize her in her pitiful life.
She wouldn't be recognized this way if she ran into an old acquaintance of hers. She wouldn't have to watch the surprise in their eyes, or the pity or the glee, at how far she had fallen, at how her lofty aspirations had been dashed.
Later, the burqa hides Laila's fears and her grief from her daughter, Aziza, when Laila is forced to leave Aziza at an orphanage.
So, for both Laila and Mariam, the burqa is an instrument and symbol of oppression, as well as a means to hide dangerous emotions like fear, anger, and distrust, emotions that are not sanctioned by the oppressive culture they live in.