To do that, you'll use the mouse wheel, similarly to how you zoom in or out on maps or photos.
Its interface, though not super attractive, helps you locate files by navigating with the zoom feature, giving your directories and files a physical appearance. In fact, you'll be able to view text files, videos, and images themselves by zooming in on them.
In Eagle Mode, the entire file system is located in a sort of room where you can also find some of the program extras, like a chess game, an analog clock, and the program's help manual. If you keep zooming out, you'll see that the room is located in an eagle's eye.