This should be posted on /r/awwscience
The cat is sitting on the base of the lamp and effectively becomes an extension of it, allowing it's owner to control the lamp's setting. This is because the body has the ability to store an electric charge.
This phenomenon is known as capacitance.
As the lamp is set to detect a change in capacitance, the combination of the cat and it's owner's touch to the cat’s nose is enough to switch the lamp on and off.
This must be the Boop on, boop off light.
I have one of these lamps and later today I'm going to have a very grumpy cat when I try to replicate this with him...
That's a bright cat. And then it isn't. And then it is
What? Someone please ELI5.
I laughed way too loudly and for way too long watching this...but damn did I need that.