There are several magic mirrors in the King's Quest universe.
The most famous is Merlin's Mirror located in Castle Daventry's throne room.
Another magic mirror was the Magic Statuette of a nymph found in Eldritch. The nymph kneels over a mirror like pond.
Another magic mirror which was shattered turned Icebella into an Ice Queen freezing her heart with one of its pieces.
Another set of magic mirrors, the mirrors originally devised by Owen in his floating castle. The set of three mirrors allows the user to see from one mirror into another, or to even move physically between the mirrors. One was located in the castle's study (in the keep), the second in the great tower (in a small chamber in the first story), and the third was in the quarters of Princess Lydia.To use the mirror one must touch three symbols in a specific order, and then recite the proper spell phrase; "You are a window through which I can see. You are a door through which I may walk. You are the way between the High and Low Kingdoms. Open, as Owen bade you."
The frozen shards of one magic mirror, turned Icebella into a cold being of ice, with a frozen and hardened heart. That mirror had the malevolent power of reflecting all good and beautiful things as ugly and deformed. One day the mirror was dropped and pieces of it, most as tiny as the smallest grains of fine sand, were scattered by the winds throughout the world. If a grain entered someone's eye, they would see the world as an ugly place. If one entered a person's body, their heart would turn as cold and solid as the hardest ice. And this is just what happened to Icebella.
There once was a fair prince, who was eager to find a bride. He looked into a magic mirror and saw the loveliest of women, but he did not know who or where she was. Often he looked upon her and once saw that she was looking into her own magic glass, and in it was his own image. He was looking at her looking at him. This sent him into the world where he finally found her and they lived happily ever after.
Snow White's stepmother, a wicked woman had a magic mirror; its power was to tell who was the fairest woman in the land. For years, the new queen asked the same question: Looking glass, mirror, on the wall, Who's the fairest one of all? To which the mirror would answer.
Another Magic Mirror allowed passage between Town Hall palace's powder room and Archduke's office.