Lecture chap 19 traded options example 3

Hi, John. I have a problem about the part b of example 3. It says show what will happen if the spot rate in April is $/£ 1.4100-1.4120. In the video, you first convert the transaction at April spot rate 1.4100 and then claim the difference from the delear to calculate the net payment. I don’t know why we should treat the exercising process apart just like the currency features. Since we exercise the option, we already know the payment would be22*31250. Why bother so much ?