OEMs such as Google, Samsung, and OnePlus usually make it a point to port features from their latest flagships over to older devices. For example, the older Pixels recently got the Pixel 4's Astrophotography camera mode, the Galaxy S10 series got support for DeX for Windows/Mac, and older OnePlus devices have received features such as Zen Mode, DC dimming, and more. However, it appears that one of the Pixel 4's lesser-known features won't be making its way to its predecessors. The Pixel 4's screen attention feature keeps the display on as long as you're looking at it. We've seen this implemented (badly) in other Android Forks, and Google seems to be the only people who managed to get this right.
Google's reason for not porting Screen Attention remains unclear
Unlike the bevy of Motion Sense gestures, Screen Attention doesn't use the Project Soli radar. The idea behind it, however, is rather creepy, as your phone is effectively looking at you at all times. Google maintains that the images are never stored or sent back to the mothership, though. In a statement to Android Police, a Google spokesperson confirmed that Screen Attention would remain exclusive to the Pixel 4 for now. It is possible that Google wants to keep some non-Soli features exclusive to the Google Pixel 4. Besides, a lot of Pixel camera features seldom remain exclusive thanks to third-party Google Camera app developers, who work tirelessly to ensure that the application makes its way to as many devices as possible.
We can, however, expect Screen Attention to make its way to older devices in a future release. Time and again, the Android community's petitions to Google have yielded positive results. It is had to determine just how many people want Screen Attention, considering that it involves your phone camera looking at you at all times. At the very least, we'll probably get an unofficial, community-made port.