(Excuse me UJ95x, but I believe that the OP may be referring to the updating of photo content in Photos...I sometimes get this and the thing goes on updating or refreshing library or something, interminably. If you switch off and come back later it's still doing it. A Soft Reset should fix.)
OP: If I may suggest, Power Off the phone, followed by Restart.
Edit: A sync error may also come into it. Go into your accounts and try syncing manually.
Posted via Android Central App