Dynastic backup technology allows the user's view of a multi-session disk to span all generations (or sessions) presenting an up-to-date view of all members (files).
The optimum view of grandfather, father and son will all be visible simultaneously - showing the latest versions of any member (file).
So if grandfather had brown hair on the original backup but has since changed - his hair has gone white ! - then the view you will see is the white-haired grandfather, his son (father) and indeed, if there's been a new baby in the family (grandson) then he too will be shown in the "dynastic view".