Continuity mistake: In the beginning when the photo of the Master is broken, the pieces of glass change position and then disappear altogether.
Continuity mistake: The bite mark on the photo of the Master changes throughout the movie. Sometimes it's in the middle, sometimes it's nearer to the corner, sometimes it's not there at all.
Continuity mistake: When the song in the warehouse is about to play, the record player has no crack on it, but when the song starts, it has a large crack near the top.
Continuity mistake: When all the appliances are leaving their house for the first time, the doorknob is on the wrong side of the door and the door opens from the wrong side as well.
Answer: Because it was the magnet's job to pick up the trash to be crushed. He didn't like seeing his items being taken away.