What is the first main point of the story "The Yellow Wallpaper"?

The first main point of the story is about the unhealthy understanding of women according to the male perspective. The woman in the story is dealing with postpartum depression, and the husband, who happens to be a doctor, suggests that what the woman needs is rest. This was a common diagnosis called the "Rest Cure". Women were thought to have minds that could not handle thinking at such levels, and the only way to "cure" the issue was for them to rest. So, the wife was set up in her room where her psychosis was allowed to fester. The yellow wall paper then became a fragmented part of her own mind, one in which she felt the need to tear away in order to rescue the woman trapped behind.
The Rest Cure, unfortunately, had a similar fate to many women to whom it was prescribed to. Because of this novel, and other stories on the horrific practice, the "cure" was reexamined and done away with later on.

In this story, we see how the narrator's health rather rapidly declines as a result of her husband's (who is a doctor) treatment of her mental illness.  He essentially confines her in a house that seems to be used as a sanatorium, prohibits her from working or meeting with other people, and takes away all means to read or write.  She is to have no mental stimulus whatsoever.  These conditions slowly drive her from an illness which is probably postpartum depression toward a total dissociative break in which she imagines that she is no longer herself, but rather a woman who has been trapped in the wallpaper of her room.  We see, then, that late 19th-century methods of treating "hysteria" are not only ineffectual, they sometimes make the illness worse.  I believe that this is one of the most significant points that Gilman wishes to make because the circumstances of the narrator's mental decline are so great that they are tantamount to tragedy: a young woman literally goes mad because her husband has imprisoned both her body, in the top floor of this house, and her mind, by banning her from any intellectual activities that once gave her pleasure and purpose.