George is so calm and cool that he doesn't really know what he's feeling unless he thinks about it (59). Lydia is so emotional that she can't put into words what's wrong with the nursery (3). While Lydia dislikes the technology, George is a big fan (at first). When she cries, he laughs. They're opposite almost all the time.
But as the story goes on, George comes around to Lydia's side of things, in part thanks to David McClean's mentoring. Which helps explain how the two end up together at the end.