All changes made by Android's Adaptive Brightness feature are illustrated by system brightness sliders in real time on Android P, one Reddit user discovered. Previous versions of the operating system wouldn't automatically adjust the sliders while the functionality was changing the brightness of the screen, whereas the severity of that shift can now be monitored on either the Quick Settings panel or via the actual Settings app which will even change brightness percentages in real time. Some users are reporting the automatic brightness transitions triggered by the feature are now more gradual and consequently not as immediately noticeable while they're happening, which may be why Google's engineers opted to implement a real-time visualization of the shift.
Adaptive Brightness changes are now also said to be less frequent, though reports on the matter remain conflicting and Google itself hasn't mentioned any changes to the fundamental mechanics of the functionality. At least one user claims the feature now actually controls absolute brightness instead of relative one, thus being more similar to some custom implementations from third-party smartphone makers. In practice, the reported change should benefit the reliability of the service as it's more likely to make the screen slightly too bright instead of too dark, consequently lowering the number of times a manual intervention is required in order to make the display readable. Adaptive Brightness has previously been the subject of some vocal criticism on the part of Pixel and Pixel 2 owners, some of whom claimed the functionality was too sensitive and prone to making constant changes at the slightest shift in the amount of lighting hitting the ambient light sensor even if such phenomena did not impact the visibility of the screen.
The first developer preview of Android P officially debuted yesterday and is presently available for download. As it's exclusively targeted at developers, the OS build can only be installed by being manually flashed onto the Pixel or Pixel 2-series flagships. The firmware introduces some minor visual overhauls and a wide variety of backend improvements meant to accelerate app development and provide programmers with additional tools for bettering their software and experimenting with new use cases. The second developer preview build is scheduled for an early May release and the OS is meant to hit the stable channel by late summer, according to Google's official Android P roadmap.