feedback reminder icon for mail trades

currently i have an international trade, that is marked as finished (both parties marked the cards as received), but in the trade window, there is nothing showing that i still need to leave feedback for the trade - currently i'm not home to check the cards, i just have been notified, that they have arrived, i usually leave feedback after verification.
an icon would be helpful, just like for local trades, where it says that the trade is not applied yet.