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)
Visible crew/equipment: When the boulders start to roll into Goblin City, just after someone yells, "Good Grief" and just as the guards start to gather together, on the left of the screen a bug is seen going down a wall, then it's seen going up the wall, and the wire is visible. (01:24:30)
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: 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)
Visible crew/equipment: In Goblin City, a small boulder jumps into the mouth of a cannon just as a guard yells, "Fire!" After exploding, the guard then says, "Hey, I just fired you," as the "cannonball" hops around near the cannon yelling, "Ouch, ouch, ouch!" and the wires attached to it are visible. (01:25:30)
Visible crew/equipment: Sarah runs to the edge of one of the platforms in the Escher-style room, and sees Toby. Just before she jumps, as she runs to the edge, a safety wire can briefly be seen attached behind her. (01:26:30)
Visible crew/equipment: After Sarah calls out "Toby!" in the Escher stair room, she jumps off the ledge. She then drops downward and lands amongst a variety of stone objects that drift all around her. The lines that the stone objects hang from are seen. (01:30:30)
Visible crew/equipment: As "Chilly Down" ends, Sarah is pulled up the ledge by Hoggle. When it shows Sarah, and the Fireys flying behind her, above the first Firey that flies up, the wires are seen.
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.