"The last picture of his father"
Translation:La dernière image de son père
I struggle with this, but I think "La image dernière de son père" is "The final picture of his father" and they are looking for "The latest (or most recent) picture of his father." Dernière can go on either side of the noun it is modifying, but its meaning changes. To make it even more confusing the sentences have slightly different meanings but can only be distinguished by context in English.
Ancien, certain, cher, pauvre, prochain, propre, seul and simple all do this as well. It trips me up almost every time.