[SubMareener]

The picture was probably taken with a digital camera with a “rolling shutter”. So the top of the screen is older than the bottom.

https://youtu.be/dNVtMmLlnoE

[nicepaco]

Thanks. I believe your theory is correct. Good video too.

[ml/nj]

This is all very interesting. I don't know how a digital photofinish camera works, but back in the film days, the film moved at about the speed of the horses being exposed to a very narrow slit at the finish line. So the picture was actually an image with time along the horizontal axis; to the right earlier, and to the left later. This is why horses legs are frequently distorted in these photos.

I would assume that if digital cameras didn't work, that the racing folks could just stick with film, so I suspect that something else is in play here. (My guess is that the mirror was not perpendicular to the line of sight of the camera.)

ML/NJ