There are three boxes, a red box at (0,0,-5), a green box at (5,0,0) and a blue box at (-5,0,0). Try moving around the scene to explore how the world position of the camera, and the eye coordinates of the boxes, changes. On the left is the 3D view, on the right is the 2D view.
Keys: w=forward, s=back, a=left, d=right, mouse=rotate camera, q=up, z=down.