I have a problem understanding this, can someone give me an answer ?

I tried to buy new iphone from banana IT, but the phone must be unbox and activate before it leaves the store ..
same with other apple authorized resellers. Why I have to unbox and activate in the store ? Can anyone explain me ?

So I bought from Apple Central World, no need to open and activate in the store...
Why like that ? Confusing.
Can someone who works in Apple authorized resellers Thailand explain this ?
I have hard time understanding why customers have to unbox and activate in the store ?