Well here is one way to give that wow gold item from that box to someone TRUSTED
You get those boxes and open them then find that you can not transfer, trade, or sell elixirs or certain potions. Well here is one way to give wow gold that item from that box to someone TRUSTED.
I would give them like 10 boxes to open. Then they open the boxes and give you back all the stuff that will transfer back to you.
The stuff that will not transfer is the stuff that you wanted them to have anyway. You will have to go to "Item Malls and AP" to see what items are transferable and not. Any elixirs are not transferable like are the training pills too.
I have 250 training pills and no way to sell them. Impossible for me to use that much too. loll Well enough to last me 10 years anyway, if I live that long, loll.
Conclusion: Just a usual way to transfer event items which are sometimes non-transferable. You might use this procedure once a year, but it is good to know and have back in your mind. Remember, this is for event drops now or just plain items.
If you want to transfer pets, you will need a trusted friend to do this.