Revealing mistake: When Sarah defeats Jareth, you can see levitating arches in the background. If you look closely at them, however, you can see the wires holding them up.
Revealing mistake: When Sarah attempts to cross the bridge and winds up holding onto a tree branch, Hoggle gasps, revealing the actor's face inside his mouth.
Visible crew/equipment: Jareth says, "Sarah, don't defy me," and tosses the snake at her neck. In the next shot facing Sarah as she holds the snake, a crew member's hand is seen holding the end of the 'snake' below her right shoulder. (00:13:25)
Visible crew/equipment: After Sarah meets Sir Didymus at the Bog of Eternal Stench, Sir Didymus climbs on Ludo's back. While he is up there, the bottom portion of Didymus' right hand 'puppet control rod' is seen being controlled on Ludo's right side. The top portion of his right hand control rod is seen many times throughout his shots. His left hand control rod is concealed as his staff. (00:58:20)
Visible crew/equipment: When Sarah and Hoggle are in the Bog of Eternal Stench and they almost fall in, look in the top left hand corner of the overhead shot and you will see a boom microphone. (Only on Blu-ray edition). (00:53:40)
Visible crew/equipment: In Goblin City, six guards gather together and one says, "Steady men. Hold your ground." The huge boulder comes rumbling towards them and hits them head on. In the wide shot as they lift off the ground, the tall pipes that create the white smoke are seen beneath them. (01:24:35)
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: Sarah wears her ring on her right hand. However as Sarah begins to climb the ladder in the tunnel after she answers, "You're right," when she puts her right hand on the rung above her, the ring is gone, but it's back in the following shots. (00:37:15)
Continuity mistake: When Sarah holds Toby and says, "Knock it off, come on. Stop it. Stop it," her ring is on her middle finger. However in the wide shot, still holding Toby, she says, "I can bear it no longer..." her ring is now on her ring finger. (00:08:30)
Visible crew/equipment: Sarah's father's bedroom back doors open up and the owl flies in towards Sarah. While in the doorway, the lines that the owl hang from are visible. (00:11:45)
Continuity mistake: Just after Hoggle pulled Sarah up, away from the Fireys he is standing by the rope he used to pull her up. In one shot as Hoggle says "Down, go away" the rope is hanging down off the ledge, but in the next shot, all the rope is pulled up, away from the ledge, and is in one big heap. (00:52:30)
Visible crew/equipment: At the start of the film, when Bowie sings the word, "Underground," the last word of the song, it's just at that moment the screen goes from black background to a backdrop of trees in the real park, which is the same moment the animated owl turns into a real owl, the wire attached to the real owl's left foot is visible. There is a jess (strap) around its left foot, that is also clearly visible when he lands on the obelisk in the park. (00:02:40)
Continuity mistake: Sarah sits in her fake room, picks up the book, 'The Labyrinth' and is seen in her reflection. She then says, "Through dangers...take back the child you have stolen." When the Junk Lady asks, "Don't you like your toys?" and also when she gives Sarah the music box, Sarah is seen. In each shot the things behind Sarah's shoulders and in front of her are different, yet, the Junk Lady did not add anything between these shots. (01:13:10)
Continuity mistake: When Sarah angrily goes into Toby's nursery to retrieve Lancelot, as she screams, "I hate you!" to Toby, who is in the crib, the crib's legs are visible and there are NO casters (wheels) attached to the legs. However, in the rest of the shots, whenever visible, there are ball bearing casters on the legs of the crib. (00:06:50)
Continuity mistake: When Jareth says "And Hoggle. If she ever kisses you..." between shots, the crow perched on the branch behind him is sitting on a different branch when he says the last part of the dialogue. (00:48:30)
Visible crew/equipment: When Hoggle is spraying the fairies, before he sprays fairy number 58, two thin black wires making the fairy fly are quite visible. (00:15:15)
Visible crew/equipment: After the Masquerade dream scene, you see Sarah falling on top of a dump. When she falls, you can see the wires attached to her letting her down. (01:09:30)
Visible crew/equipment: When Jareth throws a crystal ball across the Escher-style room, it bounces near Toby, who is sitting at the top of a flight of stairs, and Toby catches it. If you look behind Toby you can see a safety wire attached to the back of his pyjamas. (01:25:10)
Revealing mistake: At Jareth's castle, in the room with the Escher stairs, Sarah sees Toby and she jumps. It's very apparent that it's a stuntwoman jumping from the ledge in the wide shot. (01:30:20)
Continuity mistake: When Sarah sees Toby in the Escher-style room, she jumps of the edge of the platform. As she jumps off, she raises one leg behind her other, yet in the next shot her legs are beside one another. (01:26:45)
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.