> '“It’s a shock when you see it,” said the woman from Almendralejo. “The image is completely realistic … If I didn’t know my daughter’s body, I would have thought that image was real.”'

Several reasons:

1) time – a fraction of the time per victim means exponentially many more

2) skill – no photorealistic drawing skill required

3) a live referent – a genuine (here, shockingly genuine seeming) nude photograph implies that someone undressed and let themselves be photographed

4) even in the presence of a referent, a drawing is not a carbon copy ("freeze frame") of a moment in real life, and is proof of nothing