As part of its Concept for Android program, Sony has pushed out a new update to participating Xperia X units. Arriving as version 38.3.A.0.94, the update brings along several changes, including ambient display. The ambient display feature allows your phone screen to wake up whenever there's a new notification. The feature can be enabled/disabled through the 'Ambient display' option in the device's Settings menu. Aside from this, the camera viewfinder now has a fixed brightness. As for bug fixes, the Bluetooth audio loss issue due to Ok Google has been fixed, so is the missed...
Source: http://www.gsmarena.com/new_concept_build_for_the_xperia_x_brings_ambient_display_other_changes-news-23196.php
