Explanation:
Sissy Jupe serves as a foil for Louisa Gradgrind in the novel "Hard Times" by Charles Dickens. A foil is a literary device in which a character is used to contrast with another character, highlighting their strengths and weaknesses.
Sissy, a circus performer's daughter, is a free-spirited and emotional individual, whereas Louisa, the daughter of Thomas Gradgrind, is a product of her father's strict utilitarian upbringing, emphasizing fact and suppressing emotion. Through their contrasting characters, Dickens explores themes of emotional expression, empathy, and the importance of a well-rounded education.