my wife's iPhone 5s (16gb) is complaining of lack of storage. When i look the storage used the biggest culprit is system at 6gb. After that is it photos at around 5gb. I guess nothing can be done about "system", but we have iCloud photo library, which is set to optimise on the phone. How come the phone isnt offloading some space from photos? My SE which is connected to same photo library only uses 3gb space...