Continuity mistake: At the end of the movie, when Portia and Andrew are lying in their "beds," they are holding hands. In all of the far away shots, Andrew's hand is on top, but in the close shots, it is underneath. (01:59:20)
Continuity mistake: While talking to Burns about his possible sexual improvement, Andrew laughs. A second later on a wider shot, he is normal and facing otherwise.
Continuity mistake: When the robot is discussing the possibilities of a sexual relationship, the level of liquid in Oliver Platt's glass goes up and down, depending on whether it is a long shot or close up.
Continuity mistake: While Andrew and Portia are in the park, his shirt swaps from opened to closed between shots.
Continuity mistake: When Sir is looking through the window at the van bringing the robot, his hand is in an 11 o'clock position in the front angles, and a 7 o'clock in the one shot from behind.
Continuity mistake: When Linda gives Andrew the teddy dog, note its nose and you'll notice the dog changes position in every single shot, at least 4 times.
Continuity mistake: When Andrew plays the presentation, Grace cuddles next to her father. His hands on her shoulders, plus her distance to her mom, keep changing between shots at least 3 times.
Continuity mistake: When Linda asks "What's an Andrew?" her sister's arms swap from folded to lose between shots.
Continuity mistake: When the crate is opened to reveal the robot inside, Mrs. Martin takes her hand to her chest. When the angle changes, her arm is down and she is repeating the movements.
Answer: She's a smart ass, know-it-all. A delinquent who never grew. I have a sister who is the exact same way.