Why does Marshmallow 6.01 look and work differently between these two phones?

A

AC Question

I dropped and broke my Galaxy S5 yesterday. My service provider gave me a S5 Neo to replace it.
Can somebody tell me why Android Marshmallow 6.01 looks and works so much differently between these two phones???
For example: On my S5, I didn't have to swipe the lock screen in order to get to the PIN entry screen. On the S5 Neo I do, and there doesn't seem to be any way to change it.
Also, the settings screen is very different between the two phones. Marshmallow 6.01 was easier to customize on the S5 as compared to the S5 Neo.
Anybody know why it is different between the two phones?