Not listening.
Hold the button, or hold the space bar.
What happened
What it heard
What it answered
What this can and cannot do here
Said plainly
It does not wake when you call its name. Browsers cannot listen in the background, and this build has no wake-word model. You press, then you speak.
It does not know who is speaking. There is no voice recognition of people here. Anyone who can reach the microphone can talk to it, so do not use it to approve anything that matters.
Speech is turned into text by your browser. In most browsers that means the audio goes to the browser maker's servers, not ours. We receive only the text.