The focal point for this shot is the house where Agatha and the twins live out the rest of their days in Minority Report. Because it contrasts with the warm, yellow of the rest of the shot, it makes it stand out that much more. It could say something how the people in the house had led dark lives, but personally, I think that's reading a bit too much into it. I think this ended shot is a perfect symbolism for " And they lived happily ever after."
It's also the only man-made thing in sight and there's nothing else to distract our eye with, except for maybe the lens glare or the land masses in the background. It's simple, yet the house makes a big and strong focus.The house is in the foreground, and really the only thing that's in it because it's the main focus. Everything else is in the foreground, making it a little bit less insignificant.
While the focus for this shot, the house, doesn't follow the "rule-of-thirds" rule, the background certainly does. The land mass beyond the patch of water is framed to be on the top horizontal of the rule of thirds rule. And while the land mass that holds the house extends past the bottom horizontal, the house (the main focus) is on the bottom horizontal. Although it's for the most part centered, it makes the audience feel comfortable and easy and leaves them with a feeling of completion at the end of the movie.
