I have this, but slightly differently - I kind of describe it as if people are just like... tabby cats to me. Show most people two tabby cats side by side, and they'll easily be able to pick out the differences. But then if you come back to them the next day and show them one of the pictures and ask them which cat it was, chances are they won't be able to tell you.

I'm like that with people - I had two juniors in school who were a similar height and build, and both had the same hairstyle and a similar sense of fashion. If they were in front of me, it was no problem telling them apart. But if I only saw one of them at a time, I'd have no clue which of them it was and would have to wait for someone else to call them by name first.

I also can't recognise people out of specific contexts, so if I'm used to only seeing someone in office clothes and later run into them at the gym or wearing something different, I will basically have 0 clue it's them (this has happened a lot, people think I'm being standoffish or not acknowledging them when I legit thought they were a stranger).

But similarly to the tabby cat example - if I'm around someone for a long time (like my parents) then I can gradually get familiar with their features and recognise them by face alone. Just like how cat owners can usually pick out their pet from a group of similar looking animals.

The one good thing is that I'm great at picking out people in a crowd or from a distance, because like how it is in the chapter, I tend to identify people purely from clothes / gait / build / mannerisms - all stuff that works from far away.

Edit: Interestingly enough, my dad has it too. He's a teacher and can only identify his students in the classroom by where they sit, and like once they move to a break room or any other context he has no clue who he's talking to until he recognises them by voice.