Could you please tell me the literal and symbolic or metaphorical meaning of "bantering inconsequence" and "cool" in this excerpt of the first chapter of The Great Gatsby?
Sometimes she and Miss Baker talked at once, unobtrusively and with a bantering inconsequence that was never quite chatter, that was as cool as their white dresses and their impersonal eyes in the absence of all desire. They were here—and they accepted Tom and me, making only a polite pleasant effort to entertain or to be entertained. They knew that presently dinner would be over and a little later the evening too would be over and casually put away. It was sharply different from the West where an evening was hurried from phase to phase toward its close in a continually disappointed anticipation or else in sheer nervous dread of the moment itself.
In this context, Daisy and Jordan are talking quietly and without attracting too much attention to themselves ("unobtrusively"). They are not quite at the point of "chatter" meaning that they are not only talking about trivial things. "Chatter" tends to be about trivial, everyday things. They are bantering (talking informally, maybe with humor and inside jokes) and from Nick's perspective, their banter is inconsequential; in the greater scheme of things, they are talking about things that are not of great significance. That is to say, their "banter" is informal and of no great consequence; to Nick, they are surprisingly casual. This atmosphere of a dinner with guests is contrasted to Nick's experience from his more rural, Western background. In the West, Nick recalls:
It was sharply different from the West, where an evening was hurried from phase to phase toward its close, in a continually disappointed anticipation or else in sheer nervous dread of the moment itself.
Nick is surprised at how casual the dinner is, but he is particularly surprised at how informal Daisy and Jordan are. Nick implies that in the West (Midwestern America), they would have been more formal in speech and attitude.