To yank a wrinkled piece of clothing downward after putting it on, therefore straightening it out (kind of) in the absence of a time-intensive ironing process.
Julie: "Hey Brad, uh, that shirt's kind of wrinkled. You sure you want to wear that to your first date?"
Brad: "Wrinkled? I'll just man iron it!" (Pulls shirt down hard multiple times.)
Julie: "It's still kind of wrinkled. And now the collar's ripped."
Brad: "Women don't really notice these things, right?"