In the flashback at around minute 18, when Lyla levitates a block of ice, the wires from which the block is suspended are visible.
At 0:18:57 there is a flashback to an earlier scene where they are levitating a block of ice. In the flashback, you can clearly see the rigging used to hold the block of ice during production.
When levitating the ice block it looks fine but later on in the flashback you can clearly see the wires they forgot to paint out.