Sorry, I didn't see that this was in the context of the earlier questions.
At the moment your screenshot was made, you are in your Action phase, so you can play only Actions, which is shown by your Action cards in hand having a green outline (green means "can be played").
You can play Throne Room/Smithy as normal, so you can draw 6 cards alltogeher.
Or you can play any of the Actions cards using Way of the Goat. If you do that, by clicking on the Goat picture on Throne Room or Smithy (marked with a red ellipse), you tell the game you want to play the card using Way of the Goat.
Once you do that, the Smithy in play will get the Goat picture to remind you that this is how you played it and all cards in hand will be marked with a red outline, indicating that they can be trashed:
The best play in this situation (as best as I can see) is to play Throne Room normally, then let it play the Smithy twice, and you choose to play Smithy using Way of the Goat each time. This allows you to get rid of both the Curse and the Estate. I just did that on reload of the game, and it worked as it should.
If anything is unclear, feel free to ask!