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Every word Daisy says reflects the wealth with which she surrounds herself. Gatsby recognizes this fact and makes the comment when Nick is trying to excuse Daisy's insensitive comments.
Gatsby may have been remembering when he first met Daisy, visiting her parents' mansion in Louisville when she was a teenager and he was a young officer in training before being shipped overseas.
Gatsby may have been recognizing the vast but superficial social world that Daisy loved. Her goal in life was to be surrounded by beautiful people sharing beautiful experiences, without being concerned about developing any depth to any of the relationships.
as we strolled out among the sparkling hundreds, Daisy's voice was playing murmurous tricks in her throat. "These things excite me so," she whispered.
Nick immediately understands and agrees with Gatsby's analysis.
It was full of money-that was the inexhaustible charm that rose and fell in it, the jingle of it, the cymbals' song of it...High in a white palace the king's daughter, the golden girl...