Check it out: it's Arrokoth in 3D! Because the two frames were taken from a slightly different perspective, they can be assembled into a stereo image. Andy thinks he has the orientation figured out properly to show something in 3D. He puts together an image pair, and uses a pair of Brian May's stereo glasses to view it. These glasses were borrowed from a copy of Brian May's 3D Moon book, which John Spencer had brought in.
The book is very cool, and a lot of contains 'serendipitous' 3D observations just like this one. You don't need to take along a discrete 3D camera to make 3D images. If you take two pictures of the same thing from different angles or different times, you can often shift and scale the images so that they'll make a good 3D pair. Brian May is great at this, and he contributed a lot to this effort later on.