When taking pictures with GPS enabled, is the 'has the "GPS searching/locked notification icon" been disabled?
I've just tried on my Nexus 4 and it does show up, although very very briefly.

I had GPS turned on, took a photo and quickly opened the app switching 'menu'. I saw the GPS notification show up for about 1 second and then it disappeared. I guess this is because it quickly grabs your location and stores that with the image, and then "doesn't care" where you are so doesn't access your GPS location again until you take another picture.