It works on the neural networks inside people's skulls. The point is a passport control officer would wave either of two distinct people through based on the same photo.
About a decade ago we had iris scanning at London Heathrow. You had to register upfront, and the idea was only frequent flyers would be registered, but it was great, the lines were short - you didn't even need to get your passport out.
It started getting a bit silly towards the end as unregistered people started clogging up the queues, but it was far faster than the "automatic passport scanning" stuff.
Surely that was harder to forge than a passport photo. I assume the company in charge didn't offer enough bribes to the politicians making the decision.
The trick also fools humans who still exist at all borders, including at automated gates (where humans get to see each comparison although I can't imagine them being to attentive at the end of their shift).
Adversarial against humans; it sounds like the idea is to take two people who already look somewhat similar and produce a photo which as best as possible looks like either.
