I'm looking at that trade, and the person who marked it sold didn't specify who it sold to. Unless you do that, you can't give/receive trust. Furthermore, if you are the seller, you currently can't give trust.
This is all changing next patch - see the common issues sticky on the main forum.
List trades and earn trust
Level up as you post
Give and Receive Likes
Discreet Notifications
Avatar & Profile customisation
Private Messaging
Bookmark Pages & Posts
Use Drafts & Revisions
Attach Images
Squelches this trader, making their offers on your trades invisible to anyone except themselves. Their trade listings will also be hidden from your marketplace.
Your squelch list can be managed and edited from Top right dropdown > Account Prefs > Squelches.
freedon
15