Your friend code changes, so your Safari will change as well. Since your friend code it random, your Safari is as well. There is a chance you'll get one similar, but it is highly unlikely.
That's what I understood too.
I reformatted the first time and got the same safari, thought that's strange. Tried again just to see what would happen. Same safari. Third time changed. Then I've tried again 3 more times yesterday and fourth time today and am getting the same safari.
My friend code has been different each time.