Final answer:
Mathilde's initial reaction to the invitation is crying over having nothing suitable to wear, manifesting her desire for a more luxurious lifestyle.
Step-by-step explanation:
Mathilde's initial reaction to the invitation is one of distress and dissatisfaction because she cries that she has nothing to wear. This reaction highlights her longing for luxury and her discontent with her modest life. Instead of being overjoyed at the chance to mingle with the affluent or worrying that her husband will embarrass her, or believing it's a cruel joke, her focus is on her own lack of suitable garments for such an occasion.