Here we have the first of the circle-traced images.

You start to see a hint of what's to come - the images are rather "fuzzy." It gets more interesting, though. Notice that the green sphere seems to overlap the blue one slightly.

This can be explained fairly easily, however. It's not difficult to imagine that some of the rays, travelling in circles, will actually get around the blue sphere and hit the green sphere. This is what your eye would actually see - an overlap between the spheres. It can get confusing. It most certainly will!

Finally, a bit more foreshadowing. If you look closely, you might notice that the spheres are slightly larger than before. This is because pixels that are more on the edge have light rays that can curve back in and still land on the spheres.