From the rulebook:
When you Plot, you play no card but you can
copy the Order from the card(s) on another
player's Domain, provided you have at least one
Activity of the same color
You copy the activity from the "card", not from whatever action they used the card for. You can use this strategically too. In our game there was a shortage of blue orders. When I had one in my hand, I chose to play two other cards to take the Trade action rather than exposing a blue card from my board and allowing other players to also take the trade action using the blue card on my domain...