If we look at The Great Gatsby with a feminist lens, as opposed to a formalist approach, issues regarding the female characters would become more apparent. However, if we approach the book with a theoretical approach such as historicism or new historicism, feminist issues might come up because a historical approach to the novel would acknowledge social, economic, and cultural issues which inevitably involve men, women, and their social relations. A Marxist approach would look at the class systems, cultural and political power, and the unequal distribution of wealth. Given that Daisy relies on Tom for money, shelter, etc., the Marxist approach could address the cultural reasons that Daisy was forced (and/or chose) to be in that position. Gender theories would also address some of the feminist issues.
But, certainly, if the reader approaches the book primarily with feminist issues in mind, that interpretation will necessarily spend more time focused on those issues and therefore the reader will discover more by focusing on that specific approach of feminism.
A feminist approach would also spend more time on the female characters whereas other approaches might focus mostly on Gatsby, Nick, and Tom.
Consider that Jordan Baker is a secondary character. Using a feminist approach, one would be very interested in her character because she seems a bit more modern and liberated than Daisy or Myrtle. Jordan is the most representative of the "flapper." Flappers were women who were more independent, didn't care for the "proper" ways a woman should behave; flappers therefore had the designation of being independent and potentially promiscuous. Here, a feminist approach would consider the double standard where men are expected to be independent and/or promiscuous whereas such behavior is condemned when women do it. In other words, a promiscuous male is stud whereas a promiscuous woman is a slut. This double standard exists to this day. Although Fitzgerald criticizes Tom, it seems to be his personality, not so much his having an affair, that the author finds repugnant.
The Great Gatsby was published in 1925. Women got the right to vote in 1920. Clearly, feminist issues were a part of that culture and that epoch. The flapper, although not a militant feminist role, was a part of the ongoing feminist movement. It is alluded to that Daisy has been loved by many men which would mean that many men desired her but it could also imply that she was promiscuous in her younger days. However, compared to Jordan, she is hardly liberated, having been married to and supported by Tom. Myrtle is like Daisy in this way; a functional character only in her relationships to Tom and George.
Fitzgerald portrays Myrtle as rude, selfish, and superficial. Jordan is the strong female in the novel. A feminist approach should pay specific attention to Jordan for this reason. Nick finds her fascinating because he is both attracted to and intimidated by her independence:
At any rate, Miss Baker’s lips fluttered, she nodded at me almost imperceptibly, and then quickly tipped her head back again—the object she was balancing had obviously tottered a little and given her something of a fright. Again a sort of apology arose to my lips. Almost any exhibition of complete self-sufficiency draws a stunned tribute from me.
Using a feminist approach, consider the ways the female characters are portrayed and how the males respond to them.