"This seems entirely understandable to me.
Out in the world in real life, if you recognize someone you know when you see them, that means that you recognize more than how they look and their name. You recognize the individual in a way that encompasses what you know about them, their personality, their relationship to you, how you feel about them, what you just remembered that you wanted to talk to them about, and on and on.
Many aphantasics say that one of the things that makes them most sad is that they cannot conjure up mental images of well-loved people in their lives who have passed away. I don't feel that way at all, even though I too am aphantasic. For me it's sufficient to say that I "know" what someone looks like (could recognize them in almost any photograph, even one I haven't seen before), but I don't feel any need to create a mental visualization in order to think about them. My thoughts include emotions, memories of singular shared experiences as well as oft repeated sayings and advice...and on and on. Having a picture of someone in my mind feels much less important than all of the rest of that, which seems a lot like how you describe how you can identify someone you know in a dream."