Since the Nvidia SHIELD TV added Google Assistant support last year, it's been slowly catching up with other Assistant-enabled devices by adding new functionality. It looks like a couple more capabilities are now available. At least we think so, as Assistant features across different devices are so inconsistent that it's sometimes hard to tell what's new and what's not.
According to Nvidia, broadcasting messages and the ability to summon your security camera stream on your TV via the Assistant are both new additions. Apparently, if you tell the Assistant on the SHIELD TV to "broadcast that it’s time to watch TV," it will relay the messages to Google Home devices around the house.
Using the Assistant to get your Nest Cam or Logitech Circle stream on your TV was already possible with a Chromecast. You could also use their respective apps on your SHIELD TV, but now you can use also use your voice. Ask the Assistant to "show me my front door camera on SHIELD" and it'll appear on your TV, which is pretty handy.
We've not been able to test that out yet, as nobody here at AP (who is currently awake) has both a SHIELD TV and a compatible security camera, so tell us in the comments if this is working as advertised. Likewise, if you've been able to do this for some time and Nvidia is only now getting round to shouting about it, do let us know.