Why is Mme Loisel unhappy when she receives an invitation to an evening reception in "The Necklace"?
The simple answer is that Madame Loisel is upset that she does not have anything to wear that is worthy of the occasion. More noteworthy still is how she reacts to the invitation, showing complete contempt and disregard for the efforts of her husband to secure the invitation for her.
Instead of being delighted, as her husband had hoped, she threw the invitation on the table crossly, muttering:
"What do you wish me to do with that?"
There is much more to Mathilde's reaction than just the fact that she has nothing to wear. Mathilde is a self-absorbed woman who feels that she is entitled to all the good things in life, despite of the fact that she has done nothing to earn them, nor has she ever come from money, in the first place.
When she says that she has nothing to wear, she does not say this with the humbleness that distinguishes a good woman of limited means. Instead, she uses sarcasm and haughtiness, as if demanding from her husband--or from life itself--that she gets those things.
She even goes as far as telling her husband that 400 francs would do for a new dress (which she is only going to wear once), so she took the savings that he had put aside for a hunting trip to buy the dress. More importantly for Mathilde was the jewelry to wear. Since she had none, she had to resort to her rich friend, Madame Forestier, who lends her the necklace for which the story is titled: a necklace that gets lost, and whose replacement will cost Mathilde her entire life.
check Approved by eNotes Editorial