Well, Amanda is clearly living in the past as she prepares for Laura's evening with her gentleman caller. She wears a dress much too young for her, one she wore as a young girl in the midst of her own social whirlwind. Her insistence that Laura claim credit for having prepared the meal is part of that old-world Southern belle mentality, as is her flirting with Jim. She really thinks that's the way life still is--or else she doesn't know how to make the adjustment.
Laura, too, has created a fantasy world for herself. It consists of music and menagerie, a fragile world of melody and glass. Both are ethereal and fragile, just like her. She is, in fact, capable of becoming part of the real world, as we see in her encounter with Jim;but she still prefers her Victrola and her glass menagerie.