Final answer:
Scout and her brother experience mixed feelings about Christmas due to the duality of enjoying gifts, but also facing potentially uncomfortable family interactions and the complexities of the Santa Claus myth.
Step-by-step explanation:
Scout and her brother have 'mixed feelings' about Christmas because while it is a time for receiving gifts, the holiday also involves interactions with family members that may not always be pleasant.
For many, the festive season could include compulsory socializing with relatives who they might not see eye-to-eye with, leading to mixed emotions. Moreover, as children grow older, they become more aware of the pretense involved in the myth of Santa Claus, contributing to their complex feelings around the holiday.