Because you've posted an image of some inaccurate propaganda, thus extending it's reach. Fact checks, corrections and apologies never have anything like the same reach as the original post
Why would the dry cleaner say come again to a question that she'd have been asked thousands of times in her line of work. There's no logic to the joke, just gratuitously shoehorning the word cum onto a photo. It could be someone buying a pint of milk and the newsagent replying 'come again' and the customer replies 'no, semi skimmed'.
