I suppose that the 1st image is window on its default size, while the 2nd. one is the same window, but resized.
· Keeping this in mind, I think you could move "Game Images" at the top of the window, being "Game List" below.
· Then move these images to be left aligned and swap places between "Title" and "Preview" in order to make "Title" the first one.
· Also, I think you could allow window to show MORE or LESS "Game Images", depending of window size (I'm talking about width, since you've managed to show window contents appearance correctly, despite of their height).
· · In this case, default window size, would show 2 images ("Titles" and "Preview"), as you've shown on your first pic.
· · While resizing (or, probably better, using a "maximize" button), if screen allows, it could show more images at the right ("Select", "Highscores", "Bosses", etc) in order to avoid that "whitespace" you've shown on your second pic.