https://www.cnet.com/news/device-makers-can-roll-their-own-google-assistant-hardware-with-google-assistant-connect-ces-2019/

The chip will be small and inexpensive because it doesn't actually do the computing. Instead, it acts as either a Wi-Fi or Bluetooth bridge to a nearby Google smart device like a Google Home smart speaker. For the example of the e-ink display, the developer would program the chip with a simple repeating query asking about the current weather, the chip would send the question to a nearby Google Home, which would send back the answer. Then, the display could show the relevant info.

A device maker can program the Google Assistant Connect platform to recognize voice commands too. Google used an air conditioner as an example, saying you could talk to the air conditioner and tell it to turn off for an hour and it would respond appropriately. The chip would simply communicate the command to a nearby Google Home device and Google Assistant would use its smart home capabilities to turn off the gadget.