I don't care for the icons being all white. For instance I like an almost fully charged battery to show a green icon, a low orange and eventually red. Other things too, but this is a start.
Re: T-Mobile Galaxy S4 : Official KitKat 4.4.2 Update Discussion Thread
It's called NFC. It allows your photos, etc., to transfer to another NFC capable device when you touch them together. You can disable it in your settings if you'd like.