The woman in "The Yellow Wallpaper" is a symbol of oppression. Here we have a woman, obviously in serious need of psychological help, perhaps suffering a massive case of Post Partum Depression, being taken care of by two men: Her husband and her doctor. Not knowing neither men what she is really going through, their answers to her problems are counterproductive: Instead of motivating her with conversation and socialization, they decide to isolate her. Instead of tending to her needs, they dismiss them as the tantrums of a woman.
Basically, in her moment in time, she was literally at the mercy of the man as the head of the household, and the doctor as a protector of the family. She would be seen as a second class citizen whose pregnancy problems are now "a problem". In their heads, though her problems are caused mainly because she is a woman and women come with issues. However, when she finally snapped in the end and pulled the yellow wallpaper apart, falling into madness, she was basically sending the message of wanting to break free from a society of cruel expectations.