I think that the first example tackles such a naive approach about how to implement the discount code, IMHO I would ask more about the business logic around it. Why is a discount applied to both the order and the shipping? are they the same thing? What if the company applies discounts to only shipping and not orders itself?

Maybe it comes from experience, but I would focus on understanding the business side first and the see if the abstraction is feasible (To be honest the first approach in the example is not even bad given that they are two "independent" business entities)