Chastity
Explanation
The Joke
A woman with glasses announces to a red-haired woman: "Before I go, I intend to put this chastity belt on you." The red-haired woman asks "What?" and the first woman clarifies: "Silly woman, chastity belts don't go on your feet." In the next panel, the scene shifts and someone says "It's gorgeous. Was it crazy expensive? Take these off, they weren't included." The final panel shows the red-haired woman happily standing on what appears to be a glowing golden platform, exclaiming "NOOOOOO!" in delight.
The joke subverts the expectation of what a "chastity belt" means. Instead of the medieval device associated with controlling sexuality, the comic reinterprets the concept as a literal belt -- a fashionable accessory. The woman receiving it is delighted rather than horrified, and the conversation shifts to one about fashion and accessories rather than chastity.
The Humor
The comedy hinges on the double meaning of "chastity belt." The setup primes the reader to expect a medieval, oppressive device and the associated uncomfortable power dynamics. Instead, the punchline reveals it is simply a beautiful, expensive fashion accessory -- a belt named "chastity" perhaps as a brand or style name. The red-haired woman's ecstatic reaction to receiving a gorgeous belt completely deflates the sinister setup.
The phrase "chastity belts don't go on your feet" also works as misdirection -- it sounds like a creepy clarification about where the device is worn, but turns out to be a perfectly innocent statement about how belts go around your waist, not your feet (distinguishing it from shoes).
References
Chastity belts are devices historically (and perhaps more mythologically than actually) associated with medieval Europe, supposedly used to prevent sexual intercourse. Modern historians debate whether they were ever widely used or are largely a later invention and literary myth. The comic plays on this cultural awareness to set up its subversion.