Whatever action it is, it's triggered by your intention and your button press. You close a circuit for a very specific action and this tells a microcontroller to start counting a (random) number of seconds before initiating the exact action you intended. This is how all electronics work. In this case you don't start the device, you just start the electronic timer of the device.

At least start that timer the day before.

Maybe if your oven just turned itself on randomly and you quickly ran to put the pot in... It would probably be served a lot better by a digital assistant that you could tell to do things, as long as that's not considered a "slave".

This just feels like a "trick". As it stands today you turn on one device instead of another. And you certainly do the "work" part of the "you shall not do any work".

Yes, the delay is random. According to the manual, this was validated with experts Rabbis and is congruent with the way things should be done on Sabbath.