What makes a person attractive? From a distance, or in a photo or video, physical appearance would appear to be the key. Up close and personal, though, it is a different story. Does the person have warmth? Is the person kind, showing genuine interest in other people? Is the person a good listener? Does the person have a sense of humor? Does the person have an inner joy?
Person A may have physical characteristics that make an immediate favorable impression, but up close and personal has few, if any of the characteristics mentioned above. You didn't immediately notice Person B's physical appearance. But person B shines from the inside, having the qualities mentioned above. Before you realize it, a transformation occurs in your thinking about these two persons. Person B becomes the attractive one, and you are just glad that person A moved on.