Early on we see Hugo stealing a mechanical mouse from the toy booth. This deed tells us readers that Hugo is probably up to no good. And when he's caught, Papa Georges and Isabelle make the same assumption. All this sneaking around makes him untrustworthy in their eyes, and the fact that they take things from him (like a certain notebook) makes him think that they’re not very nice either.
But they couldn't be more wrong, right? Hugo steals for good (ish) reasons, and Papa Georges and Isabelle are a lot nicer and more understanding than they first seem. It just takes some getting to know each other before they can come to a happy truce.
So when it comes to actions in this book, things aren't as clear-cut as they seem. Sure, with some characters, their actions say it all (Uncle Claude drinks and teaches Hugo thievery, the Station Inspector doggedly chases Hugo), but for the ones who count, there's clearly more to them than meets the eye.
Besides the fact that it’s amazing that Hugo can get away with living in a train station (we thought only the Boxcar Children could live without a guardian and go unnoticed for so long), his choice of home also tells us a lot about Hugo as a person. He’s smart and good at blending in with the crowd. He becomes attached to things that he needs to fix (like the station clocks and the automaton), and in doing so, he becomes attached to the train station. That the rough-and-tumble lifestyle doesn't seem to bother him is a testament to the fact that he is, at the end of the day, a little boy.
Papa Georges’ home and work also tell us a lot about him. Everything about his life is very modest (and kind of sad) now. He lives in a smallish apartment with his wife and Isabelle, and he works at a small toy booth in a train station. His life used to be really big and exciting and glitzy, but now it’s just mundane. Where's the glitz and glam of yesteryear?
To be fair, Hugo is obviously not used to talking to people much, since he’s trying to lay low and avoid being caught by the Station Inspector. In fact, he’s probably not used to talking to people at all. So it comes as no surprise that when he does start talking to people, he spends a lot of his words throwing around accusations.
Georges Méliès calls him a thief, he calls him a thief back, and Isabelle calls him a thief later on. The cycle is one of confrontation. The same thing happens when the automaton draws its picture, and Isabelle asks Hugo where it came from:
“You are a liar!” yelled Isabelle. “You stole this machine from somewhere. You stole it from Papa Georges! The notebook probably isn’t even yours. You must have stolen that, too!” (2.1.10)
Talk about friendly conversation, huh?
But by the end, he and Isabelle are good friends (or so we hope) and the tone of their conversations has certainly changed:
“Will you carry some extra film for me tonight?” she asked Hugo… “And I’ve been meaning to give this to you.” (2.11.11)
The dialogue sure changes when their relationship does, and so it goes to show that seeing their conversations gives us some insight into how the characters really feel about each other.