Yes, I often notice this same morphing of how people look in my memory. After briefly meeting a new person and then leaving them, I often try to remember their face and find the details slipping through my mental grasp, until I’m imagining someone else, such as a classmate from high school, who I’m more familiar with and who looks a bit like the new person. When this happens, I think to myself, “oh, it’s happened again, I’ve forgotten what they look like already”.