The ironic toy
Hugo is obsessed with this broken little robot who is supposed to do something, but he can't find the key to start it. Then, as he and Isabelle are saying their final goodbyes, he realizes that her necklace looks like a fit. Ironically, it is a perfect fit. More ironically still, the toy ends up being Georges's personal invention, and it even signs his name.
Georges and Hugo's ironic relationship
Although the book is about Georges and Hugo saving each other by becoming a family, they have an ironic path to get there. Most ironic is the fact that they start the novels as antagonists. Georges is plagued by the urchin who never obeys rules and always makes everything into a game.
The irony of orphanhood
As a symbol, an orphan is ironic, because the role of a young person is to be in a family and to learn the ropes of life in a fun, healthy way. Now, Hugo still does that, but on his own, so he's an ironic character, because in lieu of his parents, Hugo just starts treating the station as home, and he treats the authorities as parents whom he bothers for their attention. He is doing the right thing, but in the wrong place, by no fault of his own. Most ironic of all is that they mistreat him for his neediness. Hugo's name seems like a reference to Victor Hugo's Les Miserables, which is also a story about orphans in serious need.
The ironic identity of the toy maker
Georges seems to the reader like a humble toy shop owner. He doesn't even run a store, but just a kiosk in the station. But actually, he is a famous filmmaker who faked his own death and is living his life in obscurity. He also happens to be a magic toy maker, which is unexpected.
The irony of magic
Magic seems like an unnecessary element of the novel, because Georges doesn't really need magic to accomplish any of his accomplishments, but still, he appears as a magician, and his toys and movies are magical, at least in Hugo's opinion. Perhaps, Hugo's imagination is influencing the reader's experience of the novel, but in any case, Georges's magical aspect is ironic, but meaningful, because it draws attention to his role as Hugo's savior.
