Marketplace/Opening boxes

If you have have boxed item, like an avatar, you'll have to unpack it to receive it. To unpack the box, you need to drag it to the ground, right click on it and choose from the pie menu 'Open', a window will open -- click on 'Copy items to Inventory' or if there are clothing in the box you can also wear them (there is an option for that).

Once you've copied the items, you can find them in your inventory.