Continuity mistake: When Sarah reaches Jareth's throne room, before she says, "Oh no," there is a wide shot of the room. When she says, "That's the only way he ..." things in the room have changed position. (01:26:40)
Continuity mistake: When Sarah leaves Toby's room, just after saying the Goblin wish, you can see two paintings hanging beside Sarah's bedroom door. They have a wooden frame, but when the shot changes, and Sarah walks towards her bedroom door, the paintings have changed, and the frame of the painting is now metal. Then when Sarah enters Toby's room again the paintings have changed back to the wooden framed ones.The bottom picture itself also changes.In the 1st shot there seems to be a bouqet of flowers but when Sarah is outside of the room the picture is of a long bare landscape. (00:09:35 - 00:10:20)
Continuity mistake: When Hoggle and Sarah fall out of the chute that leads to the bog of eternal stench, between shots, the amount and position of leaves on the ledge changes constantly. (00:52:45 - 00:53:40)
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: When Hoggle and Sarah climb out of the large pot, the table underneath the pot has dirt on it. The amount/position of the dirt changes in the following shots. (00:38:10)
Continuity mistake: In Sarah's father's bedroom, the rocking horse that sits near the back doors is seen throughout the shots in the bedroom and its positions changes several times. (00:10:30)
Continuity mistake: After Jareth throws the snake at Sarah, the Goblins around the bedroom laugh, and the one at the headboard ducks behind the pillow changing the pillow's position. Yet when Sarah says, "But I have to have my brother back," the pillow is back in the exact same position, with the same creases as before the Goblin moved it. (00:13:35)
Continuity mistake: In the tunnel as the cleaners approach, Sarah and Hoggle fall with the door as it slams to the ground near the ladder. The bottom of the ladder is surrounded by the broken door as well as other debris. When Hoggle and Sarah climb the ladder, one of the ladder rungs fall and there is a shot of the bottom of the ladder, but the debris at the bottom differs from the previous shot. (00:36:40 - 00:37:35)
Continuity mistake: When Sarah walks towards Toby's cot before pulling back the sheets, just before approaching it, there is a shot of the cot. Then in the next shot it shows Sarah reach down then pull back the covers. Between the two shots the covers and pillow have moved and changed their position. (00:10:45)
Continuity mistake: After Sarah finally asks Hoggle the right question, the doors to the labyrinth open, beside the flower vines on the wall, and the dirt ground between the doors is clear. In the following close-up, when Sarah begins to enter, the flower vines on the wall noticeably differ. Then when Ludo walks out and slams the doors, the ground between the doors is covered in leaves. (00:16:25 - 00:18:00)
Continuity mistake: When Sarah is finally back in her room, she sees Ludo, Sir Didymus and Hoggle in the reflection of her vanity mirror. Her white dress that lies on her bed changes position when seen on the real bed, the close-ups in the reflection and the semi close-ups in the reflection. (01:35:00)
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: When Sarah crosses the Bog of Eternal Stench, the bridge rails break, and then the bridge plank under her gives way and falls into the bog, while she clings to the tree limb. However, when Sir Didymus says, "It seemed solid enough," the left rail and the bridge plank are actually still intact. (01:00:25)
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: When Sarah sits down at her vanity table in her fake room, in a wide shot you can see her Labyrinth book laying on the table. The angle the book is laying at changes when Sarah picks it up in a closeup. (01:09:55)
Continuity mistake: When Sarah is talking to Jareth about entering the labyrinth, when she says "Don't you understand that I can't," Jareth is standing in front of a tall tree. But in the next shot, the tree has gone. There are just tree limbs and branches behind him, but the tree has disappeared. (00:13:32)
Continuity mistake: During the battle in the Goblin City, a Walking Cannon fires a shot at one of the rocks. When the rock shatters, the roof behind it and a jar at the right edge of the screen suddenly shift their positions - slightly but visibly.
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: Depending on the angle of the shots, things on top of the changing table and its shelves behind Toby's crib change position or disappear. The string toy that hangs in Toby's crib changes and also changes position. The wicker hamper basket changes position and the clothes that hang from it change as well. (00:07:00)
Continuity mistake: Hoggle wears a small orange jacket, and a brown leather belt (which has many objects attached to it, such as keys, a pipe, etc.,) which is attached to at the top, on the right side of his jacket, which runs diagonally across his body. However when Hoggle says "Me? I wouldn't go either way," the whole top portion of his body is visible, and you can clearly see that the leather belt is not attached at the top of his jacket. It seems to have gone in this shot. However after he says "You know your thing, you take to many things for granted," the belt is now back, reattached to the top of his jacket. (00:16:55)
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.