Its part of the feature as far as Panasonic are concerned so you can get quickly back to a known setting including white balance. A lot of people would use it specifically for that to be honest, maybe have a higher ISO and tungsten balance for indoors and then quickly revert to a lower ISO and a daylight balance when they go outdoors.  Fuji handle it slightly differently in that you have your C settings but with a different 'active' one for want of a better description if you made any chang