Continuity mistake: When the Junk Lady says, "Well, what about this? This is not junk," as she hands Sarah the music box, Sarah turns in her chair, brings the music box close to look at it and the toys piled behind Sarah are higher than her head. After a close-up of the Junk Lady, in the next shot of Sarah, she is still bringing the music box a bit closer to her as she turns in her chair and the toys piled behind her are now only up to her shoulders. (01:13:45)
Continuity mistake: As Hoggle pushes the head of the big metallic robot off, it lands close to the left foot of the robot. But when the goblin is thrown out of the robot, the metal head is now by the right foot, nearer to the spikes. (01:13:55)
Continuity mistake: Sarah is rescued from her fake house and head towards the gates to the Goblin City. Hoggle is seen poking his head out in the wide shot and then a close-up. The things around Hoggle change in the two shots. (01:14:25)
Revealing mistake: Just after they have all entered the 'Goblin City' and the giant robot materialises from the two gates, Sir Didymus's dog, Ambrosius (the real one - not the puppet) bolts and runs off towards the "metal" spikes. As the dog gets to the spikes they move and wobble - unlike metal would. (01:16:20)
Continuity mistake: When Sarah, Hoggle, Ludo and Sir Didymus enter the center of the Goblin City, a cannonball is fired at them, but it misses and it hits a clean portion of one house's white wall. However in a previous shot, the same portion of wall was covered in a black grubby substance. (01:16:40)
Visible crew/equipment: When Hoggle jumps off the wall's ledge onto the gate's metallic robot, the lines attached to Hoggle are visible. Hoggle then yells, "Get out of there!" to the controller of the giant robot. As he leaps on top of him, and when Hoggle says, "My turn now," the lines attached to Hoggle are seen again. (01:16:50)
Continuity mistake: In the Goblin City, the guards emerge from behind the walls, equipped with weapons and ready to fight. Sarah, Hoggle and Ludo run away, but Sir Didymus turns and yells "Right, charge!" But in the next shot Ambrosius cowardly runs away. Between these two shots, the actual clothes themselves which hang from the line above them change, and their positions differ as well. (01:17:25)
Continuity mistake: When Sir Didymus is being chased in the goblin city by the guards, the distances between the guards and Didymus, and the actual guards chasing him, changes frequently between shots. (01:17:30)
Continuity mistake: When Hoggle jumps off the huge metallic robot, we see him land parallel to the foot of the robot as he lies on the ground. When Sarah runs to him, Hoggle's head is now right up against the foot, while he lies there. Yet in the next shot as Sarah asks if he's alright, still lying on the ground, he is not near the giant foot. (01:17:50)
Continuity mistake: At the gates to the Goblin City, when Hoggle jumps from the metallic robot, Sarah runs to his aid. In that overhead wide shot and in the following shots, her hair changes as she speaks with Hoggle. (01:17:55)
Visible crew/equipment: A cannonball goes flying, when Sarah and the gang are at the Goblin City (The one that says "I hit something? Yes? No?") and as it heads towards the wall, you can see the wire it's attached to. (01:18:30)
Continuity mistake: The house that Ambrosius runs into has a small metal pole with thick rope tied around it very loosely. However when Sir Didymus is at the door, telling him to unlock it, the rope is now tied around the metal much more securely and is differently positioned. (01:19:10)
Visible crew/equipment: As Sarah, Ludo, Hoggle and Sir Didymus finally walk into Goblin City and reach the fountain, they face the stairs with the surrounding spike walls. In the next two shots, the Goblins appear behind the spiked walls, and in the second shot, on the right, a puppeteer's arm - wearing a short sleeved blue shirt, is amusingly visible under his Goblin soldier puppet; the top of the head of another puppeteer is visible to his right. (01:19:55)
Continuity mistake: When Sarah shouts, "Quick, this way!" and then Sir Didymus shouts, "No, not that way!" the hanging sign with the hammer hangs crookedly by only one chain. However, two shots later when Sir Didymus shouts, "You're going the wrong way!" the sign hangs properly from two chains. Then later, when the three Samurai Goblins jump in front of Sarah and the rest, the sign's chain is broken once again. (01:20:00 - 01:25:40)
Audio problem: When in the Goblin's house, Sarah chucks a plate of food in a Goblins face and says 'Hungry?' but her mouth doesn't move when she says this. (01:20:05)
Deliberate mistake: When Sarah, et al are surrounded by the Goblins in Goblin City, the first cannon fires causing an explosion in front of some buildings, one of which has a hanging sign with scissors on it. Later, after the squatty Goblin says, "Hey! I just fired you!" another cannon fires causing an explosion, and the very same shot is shown, only the first one was flipped. (01:20:15 - 01:25:35)
Continuity mistake: When Ludo calls the rocks in the Goblin city, there is then a wide shot of Sir Didymus standing by a house door, surrounded by soldiers. Between this wide shot, and the next closeup, the soldier's spears go from not being pointed at Didymus, to being pointed right close to him. The spears being pointed at him in the closeup also are different to the spears that belonged to the guards in front of him too (check the flags hanging at the end of the spears.) (01:20:35)
Continuity mistake: Sir Didymus (riding Ambrosius) is in front of the building with the hammer sign in Goblin City, when he quickly rides away shouting, "No. Not that way!" He is at least three houses away from the building with the hanging hammer sign, when it cuts to the many Goblin guards chasing him. Then, in the third overhead shot, Sir Did rides past that same building with the hammer sign - and now things like the sharpening stone table, the cart with baskets, etc., differ. (01:20:40)
Visible crew/equipment: In the Goblin city, Ludo calls the rocks and the rocks emerge. There is then a shot of a soldier on his stead, wearing orange armour, tumbling over as he gets hit by a rock. As he falls, the wires holding him are blatantly visible. (01:20:50)
Continuity mistake: When the soldiers start to fall, as the rocks start rolling in the Goblin city, in one wide shot Didymus is laughing and has both hands at his chest, with no staff. Then in the following closeup of him saying "Next time surrender" his left hand his out by his side, holding his staff. (01:20:55)
Answer: The necklace is a symbol of Jareth's power throughout the story. All the time that Sarah is in the Labyrinth, Jareth has more power than her, because she doesn't really know what she's doing, and isn't taking one particular path, just getting lucky at the right times. At the end, as we all know, Sarah triumphs, and Jareth's necklace changes to admit his defeat.