I can't tell from the picture. Have you got Low Power Mode enabled? I would try a reboot of your iPhone. If this doesn't correct perhaps you need to download the iOS from iTunes rather than over the air. Perhaps someone with greater knowledge than I has the answer. Good luck.
I just looked closer at the picture. It says it will show after using the iPhone for a few minutes. Unplug and use it and check again. That could be it.
I waited a long time and nothing happens.
It wasn't connected and I have Low Power Mode enabled but when I took the picture it hadn't kicked in because there was enough power.
I rebooted and no difference.
Was down from 42 to 18% at 2:00 PM today without any use at all.
Had just recently worked.
Updated to 9.1 Short test and seems fine.
Had a long FaceTime session and sure enough, usage by app was there as I expected it. It wasn't on my iPad, that I hadn't used.
Thanks for the help