Have a look at below image:
As you seeing that, when i take my cursor on StackOverflow icon, it shows 1577 reputation points, but it is actually 1584 this time . (it happens Not for only SO icon, but for all the associated accounts)
I have checked this by refreshing a page many times and even also loggin out many times, as i think it may be updated soon.
So, for updation of SO reputation, Meta-SO reputation, SuperUser reputation point to the area51 or any inter-related site, what is the actual delay time for updation? i think this should be changed to the associated account quickly as and when the reputation point is updated.