There are actually 2 processors in the devices. 1 that constantly listens for a keyword, Al la, Alexa, Hey Google. When it hears it it quickly spins up another “computer” that then sends your voice back and forth to the servers for processing and response. It’s part of the reason that the listen word isn’t easily customized.
Could be either of those! It’s just me in here. But I use github.com/Fmstrat/lcs to seed my server with a bunch of stuff so I can subscribe to what I want to see. Or reply with my own account on my own server!