The boy was a huge X-Men fan, and Cyclops was his favorite. The scene originally called for Cyclops to look at the train schedule, but according to Bryan Singer the boy could not stop smiling at James Marsden. Finally, during one shot, Marsden just looked back at him and smiled, much to the boy’s delight. Bryan Singer liked the idea so much, he kept it in the film, and told the actress playing the boy’s mother to react the way she did.
I really hope this is true, but I’m skeptical.
Why would Singer be shooting the boy if it wasn’t planned? Why would he be shooting Cyclops from the boy’s perspective? It’s entirely possible that the kid’s favorite X-Man was Cyclops (though really, whose favorite X-Man is Cyclops?) but there is no way this was accidental.
It could be that this wasn’t the original take where James Marsden smiled at the kid. Maybe Bryan Singer reshot it after watching the kid’s reaction the first time.
I don’t know, it’s a cute story that I want to be true.
Though yeah, Cyclops being someone’s favorite is pretty weird in itself.