Strange things happening on my Nexus devices' lockscreens

I have a Nexus 4, a 2012 Nexus 7 and a 2013 Nexus 7. After the 4.4.2 update, the 2012 Nexus 7 has a transparent status bar and a transparent navigation bar. Strangely, the 2013 Nexus 7 and the Nexus 4 have a transparent status bar but no transparent navigation bar. Anyone else getting this?