Maybe we're so focused on making eye contact that this is all our brain can focus on --making eye contact, and forget about the rest of the features. "Look them in the eye. No, both eyes. No, not for so long, now you're staring. Quit staring. It's been a minute, look them in the eye again. Am I squinting? Oh, a fly!"
I'm half kidding. I have considered that maybe prosopagnosia had to do with me not making eye contact, but then I realized 2 things: there are people I can comfortably look in the eye (my parents or boyfriend, for example), whom I still don't recognize, and even after forcing myself to look other people in the eye more, nothing has changed.
I will recognize people based on context, and while I have mentally stored lists of features for most people I know, it usually takes me way too much time to retrieve said list and match it to the person greeting me to return their greeting in a natural way. So now I just say hello back, and hope that the list-matching tasks runs fast enough in the back of my mind for me not to say something wrong. It's not like I use people's name much when I talk to them anyway, so usually it goes unnoticed, for the most part.
I didn't know this was a thing until I casually mentioned it in a conversation 7 years ago, so I'd never realized other people weren't like that, and I was amazed at how many other people seemed to process that information so much faster than I did. And even to this day, I still realize new things about prosopagnosia, mostly from discussing people who don't have it and confronting our experiences. I'd never realized until 2 months ago, when someone asked me about recreating familiar people in my memories or dreams, that I could recreate them from the feet up to the neck, and then they had a blurry-ish head with very clearly defined hair. Eh, at least they're not Sleepy Hollow, I guess. But it had never occurred to me because I had never tried to recreate memories in my mind, and there are rarely people in my dreams, including dreams about given people. They're just assumed to be there, mentioned, and hanging out in a different room, as far as dreams are concerned, which wasn't particularly striking since this is how it mostly is in real life anyway.
One thing I don't think we've mentioned here in past prosopagnosia posts (but I might have missed some), is recognizing our own selves on pictures. It takes me a fraction of seconds to understand that I am, indeed, looking at myself, followed by a very systematic "Oh, so this is was I look like?"