Star Wars - Episode II: Attack of the Clones

I recently re-watched part of a scene in Attack of the Clones in order to verify some dialogue for a future post about an episode of The Clone Wars on my other blog.  While doing that, I noticed a significant detail in the conversation that Anakin and Padmé have while she's packing in her apartment.

After Anakin claims that "in some ways, a lot of ways, I'm really ahead of [Obi-Wan]," expresses his frustration that Obi-Wan "won't let me move on," and gives a further list of complaints, Padmé placates him by saying, "All mentors have a way of seeing more of our faults than we would like.  It's the only way we grow."  In a sort of defeated manner, he admits, "I know" and sits down.  Padmé then says, "Anakin, don't try to grow up too fast," and he replies, "But I am grown up."  Significantly, he stands up as he says this, as if trying to prove his point by showing that he's taller than she is.