Ele Headpiece

Noob question:

So I recently made my first ele after 4 years of GW. I was looking to buy her elite armor when I noticed something. How come some eles have a headpiece that hovers around your head (the fire headpiece for example) while others only have the normal one that floats in front of your forehead? How do you get this headpiece?

http://wiki.guildwars.com/wiki/Elementalist_headgear

The headpiece that floats around your head is from factions, while the rest of them are from prophecies, nightfall and eotn.

Thanks for your help ^_^