How does "Apply new privacy to your existing items" works?

Hello. In in editing profile page privacy settings there is checkbox Apply new privacy to your existing items. Before it was something like "Reset to defaults values".

Now it changed and I can't understand how it works for Profile, Points, Friends, Followers, Achievements.

I can imagine how it works for videos and photos (it will apply new privacy for old (existed) videos and photos) nut can't understand about other items.

Thanks.