Something I've heard repeatedly is that Attack of the 50-Ft. Woman is a example of classic feminist science-fiction. It's available on Netflix instant streaming, so I decided to give it a look. It does not hold up. It might have been a refreshing change of pace back in the '50s, but it's not really feminist. The titular woman is never treated with respect even when she gets power at the end. It's more about having a horrible male antagonist than having an appreciated female protagonist. Also, the subtly sexy scene in the poster never occurs in the film.
The gist of the story is that there's a rich woman named Nancy who has this horrible husband named Harry. Harry cheats on his wife with a woman named Honey. The whole town knows about the affair, but Harry pays them off. Honey suggests to Harry that he kill his wife to get her fortune and then he and Honey could be together. He doesn't seem terribly put off by the suggestion.
Out driving alone, Nancy sees an alien spacecraft land on the highway and a giant come out and reach for her. She runs away and tells everyone about it, but no one believes her. Even the UFO-sightings guy on TV who provided exposition at the beginning discounts her claim. Harry pretends to love her and comforts her. She suspects the affair but wants him all to herself because he's clearly a great husband. They go out looking for the spaceship, find it and the alien, and escape again.
Harry tries to have his wife quarantined or committed or something (it's kind of hard to understand). There's a doctor trying to calm her down with some medication. Honey notes to Harry that an overdose of the drug will kill Nancy, so he tries to kill his wife. She's turned into a giant, though. The doctor and his associates tie her up and try to keep her sedated, but she eventually gets so angry at Harry cheating on her that she breaks out and goes on a rampage.
At this point, it's all about her wanting Harry for herself. She ransacks the town looking for him, accidentally kills Honey, and lifts (a remarkably doll-looking) Harry up into the air and carries him off. The sheriff shoots at her, which has even less effect on her than the miniature WWI soldiers had on full-sized people in Indian and the Cupboard, but he accidentally blows up a power transformer and knocks her down. Both she and Harry are killed. The sheriff makes the meaningful ending statement that she finally got Harry all to herself.
So, basically, the early feminist nature of the film is that the protagonist is female and she has an evil womanizing husband. While that aspect might have made 50-Ft. Woman unique among movies back in the day, it is a very weak claim to feminism by today's standards. The protagonist is just not respected at all. When she finally becomes powerful and goes on her rampage, we don't feel for her. If we care about anyone at that point, it's the sheriff. Nancy is treated like a big wild animal that needs to be put down like Zilla from the American Godzilla.
As for the film poster, that scene isn't actually in the movie. I've seen the poster several times, and each time it's occurred to me how impractical her outfit is. I now think that was probably the point, though. They wanted her in kind of a sexy outfit, flashing her panties to the people below her and showing her breasts to the viewer. It brings in the sexual male viewers despite having no actual sex in the movie. Not only is she disrespected in the movie, she is also disrespected in the poster in an entirely different way.
So, yeah, Attack of the 50-Ft. Woman does not hold up as a feminist film. The evil husband isn't enough; the wife needs to be respected too. Nancy isn't respected at all, so I don't see how it could be at all feminist. If you want feminist science-fiction, watch The Stepford Wives. The original, not the remake. Or Dollhouse.