Why does a Roku TV turn on by itself after a power surge?

I have a ceiling light that goes on automatically after the power has been out (blackout).

My Roku box automatically turns back on when the power is interrupted and usually takes me back to exactly where I lost power. I don’t have their TV but their box attacked to another brand of TV. I can only assume that it’s a feature of the product

I’ve a wave machine in the spare bedroom that the grandsons sleep in we leave it on at night for them a nightlight in the bathroom.
The wave machine will come on after a power interruption We hear the breaking waves.