Continuity mistake: After the pool incident when David is writing letters. Monica is looking over the letters that David has written. There's a point where you can see that she's still holding at least 2-3 sheets of paper but when the camera shifts back to the writing there's only one in her hand. There should be more than one paper in her hand. And when viewed from behind her back the sheets are neatly lying on top of each other, when seen from the front, the sheets are tilted. (00:46:43)
Continuity mistake: The poem displayed in Dr. Know's booth and the one on the door in Manhattan are slightly different. Dr. Know displays the line "waters and the wild" whereas the poem on the door read "waters of the wild." (01:26:30 - 01:34:10)
Continuity mistake: In the scene where they are operating on David after he ate the spinach, if you look closely, you'll see that the little electronic gadget that pops out of David's torso comes out three different times. (00:35:50)
Continuity mistake: When Monica first meets David, David walks out onto the carpeted floor and takes a step down to the wood tiled floor. He taps his feet on the wood tiled floor and then steps back up to the carpeted floor. He taps his feet again and turns around to face Monica. This is just before he tells her, "I like your floor." The mistake here is that Monica was pulled from the carpeted floor to the wood tiled floor before David walked in. So, David should not have had to turn around to face her because she would have been in front of him ... not behind him. (00:10:30)
Continuity mistake: When the doctor takes out the chip filled with spinach, the amount of food on it differs between shots.
Continuity mistake: When the robot catcher nets in the stray robots including David they go in the cage of the moon balloon, where David is struggling to hold on to Teddy as the balloon rises into the air. Teddy says "l'll break David" and at that point Teddy slips through Davids fingers and falls to the forest floor. Teddy then immediately runs to the top of the hill where the balloon he just fell from has already sunk well behind that hill only just seconds after falling from it. The balloon has moved far too quickly. (01:02:50)
Continuity mistake: When the boys are swimming, you can see one boy get out of the pool twice. (00:41:15)
Continuity mistake: When we see the chef mecha in the cage, he has a hat on, and it is a permanent part of his head. But earlier when he was searching for an eye in the pile of stuff, he doesn't even have it on. (00:58:00 - 01:27:20)
Continuity mistake: In the scene where Martin is convincing David to go cut a lock of Monica's hair, watch David's top pajama button. When you see David head on, it's unbuttoned, but when seen from the side, it's buttoned. (00:39:13)
Continuity mistake: When David goes to cut a little hair from Monica about half an hour into the movie she is facing left, shot of David, back to Monica, now she is facing right. (00:38:25)
Continuity mistake: They show David staring at the silver dancers dangling above his bed in which he sees his reflection. Next shot shows him down too low to be seeing his reflection. Also, there is a sound of a wind chime, however the silver dancers are not touching to make the sound.
Continuity mistake: When David smashes his robot, the first blast turns the head to the right, but half a second later it's turned to the left.
Continuity mistake: When David exits the helicopter, the right leg of his pants swaps from soaking wet to dry.
Continuity mistake: After smashing his robot, David is comforted by Hobby, who extends his left arm. When the angle changes, he repeats the previous movement.
Continuity mistake: David's father is leaning on the table, yet before David melts while eating spinach, his father disappears from the table.
Continuity mistake: In the forest, the mother says, "Only with the Meca you'll be safe", then David's hand swaps from grabbing her arm to her shoulder.
Continuity mistake: After smashing his robot, David stares at Hobby. David's jacket is closed, yet a frame later it's wide open.
Continuity mistake: During the snow, the shattered body of the Fairy disappears in the aerial shot, yet reappears in the next immediate shot.
Continuity mistake: When David kills his robot, its position on the floor plus the mess around changes between shots.
Continuity mistake: When David resurrects his mother, he moves her hair away from the left side of her face. In the next shot, her hairstyle is completely different.
Answer: The seven word code was used to activate David's imprinting protocol which would make him recognize Monica as his mother.