We have mentioned this comic book phenomenon before: a superhero (or, in this case Phantom Lady, a costumed crime fighter) can fool everyone into believing she is a different person (in this case, Sandra Knight) without wearing a mask or substantially changing in any way except for changing clothes. I have considered that Phantom Lady’s body is distracting everyone from looking at her face, but that doesn’t work. After all, from birth our brains are wired toward recognizing faces. My conclusion is that Sandra must be amongst a group of people, including her boyfriend and her dad, who have prosopagnosia, a neurological disorder that is characterized by the inability to recognize faces. It is also called face blindness. Even that is unsatisfactory, since the face blindness of those in Sandra’s circle only happens when they encounter Phantom Lady. Sandra’s beau, Don, can only recognize (in the last two panels of the story) that Sandra wears the same lipstick as Phantom Lady.
In this story, from Phantom Lady #21 (1948), Sandra/Phantom Lady’s talent for evading detection may also be explained by a different artist taking over the art after about page two or so.
I wouldn’t be me if I didn’t mention that Phantom Lady must enjoy being tied up. Based on what I see on pages 6 and 7 of the rope that is binding her wrists, a child could easily slip out. No knots!