An attacker who has a way to place multiple illegal images onto someone’s phone and into their iCloud Photo Library without their consent… it’s an interesting idea but how is it possible?
Not very long ago we would have said, "an attacker who has a way to remotely control someone's iPhone without their consent simply by sending a text message... It's an interesting idea but how is it possible?" Then we learned about NSO Pegasus and that it was not only possible, but was already being done to the phones of unsuspecting victims across the world.
There’s the whole NSO Pegasus that answers for how regarding remotely. However social engineering is also possible. Drunk out in town makes an easy target for a skilled social engineer.