Meaning of Ship to/Bill to contact:roles in Customer form

Hi All,

While defining contacts in Customer:standard form for any customer, we are entering roles (i.e. bill to/ship to) in 'contact:roles' tab.

However, when selecting contact names in SR form-->Contact/Addresses-->Bill To Address/Ship To Address, all names are coming in LOV of contact names (irresective of bill to/ship to roles defined against that).

Is this standard functionality OR we are missing some setup for this?

If all contact names are coming , then what is the need for defining bill to/ship to contact roles there?

Find attached screenshot for this.

Thanks & Regards,