He nearly tells her no. He nearly tells her that he doesn't need help figuring out how to use a manual interface. He nearly makes a total ass of himself in front of a small child.

But he doesn't.

She's been here longer than he has. She obviously knows more than he does about how things work on this-- this train that he felt compelled to walk onto, than he does. He is in no position to be refusing her offer, not when it is so kindly made. So he steps back from the terminal to give her a space to join him, and he folds his hands behind his back almost like he's standing at attention, and he says, "Yes, please."