The mirror appears as an ordinary mirror, silver in color, with intricate rose and vine decorations. An ornate lion-like creature encapsulates the handle of the mirror with its mouth. On the back of the mirror, there is a symbol that somewhat resembles a fleur-de-lis.
This magical mirror allows its users to see anything he or she wishes to see on its glass and in its current situation.
It was presumably given to the Beast by the Enchantress as his only window to the outside world. It's unknown if it has always been enchanted, or that it was originally an ordinary mirror owned by the prince and became enchanted by the enchantress along with the whole castle.
The mirror was first used by the Beast to see Belle in her room, where he hears a conversation between Belle and the Wardrobe. Upon learning that Belle wanted nothing to do with him, he loses hope that she would see him as anything else but a monster.
When Beast allows Belle use the magic mirror, she sees her father dying in the woods. With only hours left before the rose wilts, the Beast allows her to leave. He gives her the mirror so she can still see him, and to remember him by.
Shortly after, Belle uses the mirror to reveal the existence of the Beast to an angry mob of villagers, in order to prove that her father isn't insane. However, Gaston, who becomes infuriated upon learning that Belle would consider him a monster and the Beast as someone kind, gentle, and someone who she loves, takes the mirror from her and uses the image of Beast to stir up the crowd. He takes the mirror all the way to Beast's castle, and is implied to have used it to track the castle's location. From there, the mirror disappears.
The Enchanted Mirror doesn't have as much of a role in the plot as it did in the previous film. When Mrs. Potts revealed to the Master that Belle is nowhere to be found the Beast went straight to Forte's foyer and held the mirror in hand and asked it "show me the girl" , and it showed him Belle, Chip, and Philippe riding through the Black Forest, and the Beast believed that Belle was leaving (through actually she went out to find a Christmas tree).The mirror isn't seen for the rest of the film.
The mirror appears in as the same role as it did in the original. Only in this version it was an ordinary mirror owned by the prince and became enchanted along with the whole castle. Gaston also used the mirror to help him and the mob find the Beast's castle, when he snatched it from Belle.