The basic idea is an in-game window you can pull up to see what the skin of any item will look like, so that you can easily browse through all the skins and decide which ones you want for your character.
The specifics
The preview window should have a few buttons added to it to make the preview character move so you can see things like a trail left behind your weapon swing.
In the preview center you first chose which type of item you want to preview (sword, light head armor, etc). Then it displays a list of all the sets* with that item in them, with the exception of things like cultural armor that your character can’t wear. Items that merely require a lot of work (Legendary weapons, HoM items, etc) will still be listed.
If an item isn’t in a set, then it should be treated as being in a set on its own.
When you select a set you get a list of all the items in that set. Alongside each item is three buttons:
– One to add the item to the preview window.
– One to open up the items wiki page.
– One to search for the item on the trading post, if the item can be traded. If not, this button will not be present.
Since this preview center is designed to help you decide on your characters appearance, item stats will not be listed. The stats will only show if the player opens up the trading post or someone lists them on the wiki page.
As new items are added to GW2, ANET has two options for when they go into the preview center:
– When a player first acquires the item.
– When the item is added.
Either way, the wiki page linked to won’t exist until players get to work on it.
*By set I mean things like Peacemaker’s weapons or Aristocrat armor. Sets of items with a common theme.