Here's why:
* The Mirror of Erised: This magical object, showing the deepest desires of the beholder, was initially owned by Harry's mother, Lily, who passed it on to her sister Petunia. When Harry found the mirror in his childhood, he saw his parents alive, which symbolized his deepest desire for family.
* The Deathly Hallows: The mirror is one of the three Deathly Hallows, powerful magical artifacts sought by the wizarding world. The mirror is the Resurrection Stone, a powerful artifact that allows the holder to contact the spirits of deceased loved ones.
* The Significance of the Shattering: In the book, Harry touches the mirror in the presence of Voldemort, who is attempting to claim the Deathly Hallows. Because Harry is not consumed by desire, he uses his willpower to destroy the mirror. This prevents Voldemort from possessing the Resurrection Stone and also signifies the end of his pursuit of power and immortality.
So, the mirror isn't physically broken, but rather shattered as a symbol of the loss of a powerful magical artifact and the end of a connection. It represents the end of Voldemort's pursuit of power and immortality through the Deathly Hallows, as well as the ultimate victory of love and selflessness over greed and desire.