Continuity mistake: When the Rock enters the first kid's room, pay attention to the blue building block on the floor and how it is turned. Just for the shots where the cat arrives and The Rock has to hide behind it, the block rotated 90°. It goes back to how it was a moment later, otherwise the curved path would not face the door and the Rock couldn't fly towards the door. (00:33:30 - 00:36:15)
Continuity mistake: When the Rock is giving the kid his present (a hockey stick) the paper covering it changes height in the shots. He even takes the paper almost all the way off when in the next shot it is back on.
Continuity mistake: As he is walking with Tracy, The Rock meets a random fairy questioning his attire. The guy has a single string showing above his left shoulder, doubling in the next shot. (00:12:40)
Answer: It was all Black Market merchandise. Usually not of any good use; total rip-off.