exactlyyy
Idk, I interpreted another way...
She was happy that they were getting close and reciving the expensive gift was like when you get payed for something, cuz originally they get married for money and status, so she felt hurt, even if it was silly...
She then returns the gift and says that she would prefer other way to show gratitude, like a smile, but the Duke shows an uncomfortable expression, so the Duchess doenst get mad, but hurt...
They don't know how to interact cuz they like each other but they still think the other is on this relationship cuz they signed a contract. Then the Duke or the Duchess try to act according to the contract as if they dont rlly have deep feelings, they hurt each other even more
So...all they need to do is talk properly (╯°Д °)╯╧╧
I know it's probably not that big of a deal, but did they actually got in a conflict because the duke is trying to give her jewellery? 0_0
Did she have to get mad and become awkward at him just because she recieved something she didn't want? If she wants a smile instead of gifts, just tell him, no need to get so upset over it. Especially since she knew about his past and why he can't express his emotion that easily. Idk, rejecting his gift just because it's expensive seems a bit pretentious to me.