https://www.theverge.com/2017/12/8/16754308/google-home-mini-play-pause-functions-added-back

Google is bringing play and pause buttons back to the Home Mini today, after initially removing them due to an issue that could cause the device to constantly record users.

Instead of tapping the top of the Home Mini to start and stop playback as had been originally planned, owners will now be able to long press the volume buttons on either side of the device to control whatever’s playing. That extends to music, news, alarms, phone calls, and so on. If it’s playing, you’ll be able to press and hold to stop it — which can be a lot more convenient than using your voice if you’re already right beside the device.