Pansy is not used to wanting things that she cannot have. Her parents have always spoiled her, and no is not a word she is overly familiar with before Hogwarts. She is used to pushing boundaries and having them give way beneath her fingertips. Daphne is someone she expects to be interested in her, because of Pansy’s status and background and connections. It shocks her when Daphne just isn’t. There is no desire to become Pansy’s friend, to get closer to Draco like Pansy is, to cultivate the connections Pansy desperately tries to put together and it doesn’t make sense. Daphne comes from good stock; surely she wants those sorts of things for herself?
When the school panics over the monster, Daphne carries on as normal and when Sirius Black is thought to be in the castle there is no excitement in her blue eyes. Not even the great Tri-Wizard tournament gets much of a reaction out of her and Pansy starts to wish she had that sort of restraint, that power to give nothing away because what a skill that will be once they have left school and are thrown into the real world with only the experiences of a small isolated boarding school to guide them. Pansy wants to understand Daphne and she can’t. She wants to know Daphne and she doesn’t. Part of her needs to understand how she works and there just doesn’t seem to be a way.
For Pansy, Daphne stands out because she doesn’t.