Up until some time recently – possibly this patch – characters had the ability to preview armor of light, medium, and heavy types irrespective of what class they were.
I found this quite useful for a few things, mostly in helping me decide what race & profession combos I wanted to go for. Now, using the PvP locker and item codes, you can only preview armor that is the same type that your class can equip.
Was this intentional? I don’t see the harm in letting you preview other armor, especially if a guildmate has some “oh hey, look at this” item they want to share, or if you just want to see what a certain set of armor looks like.