While designed by Google, the Pixel and Pixel XL share more than a few similarities with current HTC devices. Besides appearance, it turns out the screen of both phones can be turned on/off when used with cases that feature embedded magnets in the cover…
HTC’s first-party cases often take advantage of this hardware feature to automatically turn on the screen when flipping open the cover. It seems that the reed switch was left in both Pixel devices through the design and manufacturing process.
While there are no third-party flip cases that take advantage of the switch yet, you can still put it to use. The sensor is located approximately around the ‘G’ logo on the back of the phone. Magnets placed there or on the corresponding location on the front side of the Pixel triggers the switch.
As such, placing the back side of the phone on any magnet— like those commonly located on laptops to both secure the lid and wake from sleep — will turn on the screen. Unfortunately, it’s not useful for turning off the display as the screen automatically turns on again when the magnetic field is removed.
No doubt, manufactures of flip cases will begin to add magnets to take advantage of this useful feature.