Google pixel 4 motion sense demonstrated

Pixel 4’s Motion Sense feature uses a miniature radar sensor to detect movement around your phone. It can sense when you’re reaching for the phone and will initiate face unlock, or turn off your screen when you’re not around. New Quick Gestures let you skip songs when you don’t want to pick up your phone. Just wave your hand to snooze alarms, dismiss timers, or silence your phone ringer.

How does motion sense work?

Here is a demo.