I know face blindness is a thing -- there was a great book written by a scientist who had it. He said he could no more differentiate between people by their faces than if they were holding up a paper plate with two eyes and a smile drawn on it. (That wasn't what the book was about... just a side road he went down explaining something else.)

My husband claims it's because I perceive auras, so when I think of "a person" I know, I think of their aura as much as appearance. Which doesn't come across in a photo.

But brains are weird. My mom had something called Capgras Syndrome where she could recognize people, but the part of her brain that normally felt the emotional connection to them didn't work. So she thought the person wasn't really that person, and had been replaced by an imposter. Or a ghost of the person. When it got really bad, she thought she'd been kidnapped in her sleep and transported to an exact replica of her house, peopled by actors. Oddly, she had no trouble when talking to someone on the phone.

Like I said, brains are weird.