How do you wire it?
I'd like to know how it's wired. The picture doesn't show wires. The video doesn't do anything but show the item. Maybe tech support can work on that.
Having wired one of these thus far, the installation is fairly easy. I had an existing wired smoke detector. After shutting off the power in the breaker panel for safety, I disconnected the existing smoke detector. After that there is a power connector that comes in the box with the detector. You wire the nest's power adapter, black to black and white to white. If you have an orange or bare copper cable you can use wire nuts to cap them off. After that you screw the base plate on, connect the adapter to the detector and twist the detector into place.
You can see their user guide for more information. (See page ~12)
https://s3.amazonaws.com/support-assets.nest.com/images/tpzimages/US-2nd-gen-wired-user-guide.pdf