Secret status LED?
Something I found while flashing some firmware on my C6603. The purple dot in the image is some sort of LED that's visible to my Nexus 7 2013's camera, but invisible to my eyes, and I caught it flashing while TWRP was busy with something. I've never seen it outside of flashing .zips.
No idea what it's for, but maybe somebody here can work out what it's for and whether it does anything useful to us.
Yuga - Sony Xperia Z (LTE) C6603
Razor - ASUS Nexus 7 (2013) K008