After trying again to extract them, I now see the new files in their respective folders. They're holiday-themed icons. I can't think of anything I'm going to need or use those for, but I suppose it's better than nothing.
Of course, I'd be ecstatic if I had never bought Web Image Studio. Then I wouldn't feel silly for having tweeted and Facebooked this promotion.
What I am thankful for is that, for years, you folks offered a free yet fully-functional version of the HTML Editor. Meanwhile, there are the free lifetime upgrades for the paid version, which has proven to be a good purchase for me thus far, and for which there are some nicely-priced, regularly-updated themes.