It is very easy to set up and works on all of the devices listed in the 'device' node, and has two modes, an acknowledgement node where Google will confirm your request each time, and a PIN mode which requests a PIN number to fulfil the request.
It should be useful for example opening/closing garage doors, starting/stopping certain electrical devices, etc.
A further feature is also about to be added - being able to set the PIN by passing a msg into the device node.
Now it gets interesting, because 20 seconds (which is configurable) after the previous voice command, the device node emits a msg, which could be then used to generate a new random PIN, which can then be sent to your phone via Telegram, pushover or whatever.
So to summarize; to be able to execute a voice command if this feature is activated, it would be a different PIN number each time, which would be stored on your phone, or on your node-RED dashboard.