VFR w/ff questions

[toosox]

I understand that a flight done vfr w/ff is done on a load basis .

Fly from point a to point b using FF and then asked to report airport/feild/runway in sight , once the call is made of the target airport then get a replay --- radar services termainted Squ VFR ect.

Then doing the same point A to point B flight with FF again . close to the airfield/port/runway ect , ATC informs radar services terminted sq VFR ect. The only difference is I have not been asked if i have the field insight

Question. What is the deciding factor in asking the pilot if he can see his target (airport) and just termanating FF?

Am just confused to why some flights to the same airport are termanated a way from the landing zone and other flights there are termanated after i let ctrl/app know i have the rwy/airfield.