I've never seen a whitetail in Texas browse on cedar unless the habitat is extremely stressed. She's got plenty else around her that looks to be good nutrition and she appears to be in excellent shape, so perhaps it is the berries?
I had one under my stand nibbling at the cedar tree I was sitting in just the other day. She was being very selective though guess there could have been a few beeries but didn't notice any. The goats will strip the bark off of them before they touch the needles