I just got back from visiting my parents who were struggling to fix an unreliable dishwasher that keeps clogging, fails to dry, stinks, etc. This is PERFECT timing for that video!

A similar machine also plays a role in the 1997 movie Contact.

Hewn

If this was filmed in the late sixties using an older orthicon camera it might be an artifact of the way that the image is produced.

I’m just going from memory, but I believe the tubes used a brightness-amplifying screen kept charged with electrons that, when struck by light, would result in a brighter image that could be scanned by a beam. The downside of this technique is that a very bright area would suck up electrons from around it faster than they could recharge, resulting in a dark halo.

I think I remember some of the oldest classic Doctor Who episodes has this visual artifact, as well as some old Beatles TV recordings.