What about remembering things that you have already seen? Let's say I ask you to watch, for example, the Star Trek TNG opening sequence. Can you "rewatch" it?
I can. I can also sort of picture 'creative' images, to an extent.
However, conjuring up faces of people I've met is pretty difficult. Even my dog, which I find easier than people, can still take different shapes that are not real and I can't 'fix' it until I look at her again. If it is a person that I've only seldom met, I won't be able to recall the face at all, even if I can still recognize the person. It doesn't matter that I met the person a minute ago - if I don't make a very conscious effort to remember, I probably won't recognize them at all (and will definitely not recall the image). If I am under stress, that's even worse.
I've always chalked that up to 'being bad with faces', but there maybe something more at play, it seems.