What are some examples of Daisy hiding behind a mask in The Great Gatsby?

Daisy is a debutante who only cares about money. She is a static character in the novel; she doesn't change from beginning to end. However, the reader's perception of her might change, as we first see her through Nick's eyes as a beloved cousin, then through Gatsby's eyes as the epitome of perfection, and then finally for who she really is: a shallow, self-absorbed woman incapable of true love.

Daisy could be said to 'wear a mask' because she has created a persona for herself. She has a voice like money, expresses over-the-top emotions, and uses her feminine charm to make people like her or draw them closer to her.

In Chapter Seven, Gatsby remarks that Daisy's voice is full of money, and Nick realizes it's true: "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. . . ." Daisy's voice reminds people of money, so she could be said to be hiding behind the mask of her wealth. Perhaps she thinks people like her because she's 'the golden girl' and therefore doesn't allow people access to her real self, the girl who doesn't like them back.

When Daisy is first reunited with her cousin Nick at the Buchanan house in Chapter One, she isn't merely happy. She is paralyzed with happiness:

"'I’m p-paralyzed with happiness.' She laughed again, as if she said something very witty, and held my hand for a moment, looking up into my face, promising that there was no one in the world she so much wanted to see."

Here, Daisy uses words, gesture, and facial expression to draw Nick close to her like a fisherman reeling in a catch.

Daisy also speaks in a low voice, or a 'murmur,' to make people lean towards her: "I’ve heard it said that Daisy’s murmur was only to make people lean toward her; an irrelevant criticism that made it no less charming." (Chapter One) Perhaps Daisy feels that forcing people to lean closer to her will create the illusion that everybody likes her.

Daisy hides behind a mask of wealth and charm. But at the end of the novel, we realize that Daisy is not a lovable person when she chooses Tom over Gatsby, knowing that Tom is cheating on her while Gatsby really loves her - he even takes the rap for killing Myrtle. She chooses Tom because her real love is for his money and aristocratic roots.