Blanche's actions with Stanley are dictated by her basic nature. The woman must create an illusion. "After all, a woman's charm is fifty percent illusion." And if Blanche cannot function as a woman, then her life is invalid. She therefore tries to captivate Stanley by flirting with him and by using all of her womanly charms. She knows no other way to enter into her present surroundings. Likewise, she must change the apartment. She can't have the glaring, open light bulb. She must have subdued light. She must live in the quiet, half-lit world of charm and illusion. She does not want to see things clearly but wants all ugly truths covered over with the beauty of imagination and illusion.
But Blanche also realizes that she must attract men with her physical body. Thus, she does draw Mitch's attention by undressing in the light so that he can see the outline of her body.
When Blanche meets Mitch, she realizes that here is a strong harbor where she can rest. Here is the man who can give her a sense of belonging and who is also captivated by her girlish charms. She deceives him into thinking her prim and proper but in actuality, Blanche would like to be prim and proper. And as she later told Mitch: "inside, I never lied." Her essential nature and being have never been changed by her promiscuity. She gave of her body but not of her deeper self. To Mitch, she is ready to give her whole being.
