[iMore Question]

Has anyone figured out the rules for caller ID photos showing up full screen again?

I have some contacts that do and some that don't. I'm guessing it is a photo quality issue.

Has anyone figured this out?

[Just_Me_D]

If the photos are associated with iCloud, they should be in full screen mode when receiving calls. You can try deleting the photo and then re-adding it to see if the screen size changes when receiving a call from the person(s).

[vox separatum]

1. Click on the contact info (i) for whom you would like to receive fullscreen incoming call.
2. Click Edit (top right)
3. Click Edit under the contact photo (you will get 4 options)
4. Click Edit Photo (Move & scale options will appear. You don't need to change anything)
5. Click Choose

That's it! Next time that contact's incoming call will be fullscreen. Tested and working (iOS 8.3)