It's buried in the article, but: "Coates was moving when the photo was taken, so when the shutter was pressed, many differing images were captured in that instant as the camera swept over the scene, since it was a panoramic photo capture."

So it's a pano doing normal pano things, but it's just surprising in context. If you have not yet tried it, you can have friends jump in and out of the frame as you slowly move across a scene and have silly photos where they appear more than once!

Edit: typo