Jason Das - artist, Urban Sketcher, and website wrangler extraordinaire - identified the problem that had crept into this page's code and suggested the right fix. (A missing </div>, for you CSS fans, though how & why it went missing is another question entirely. And yes, I will fix the sidebar so it's not at the bottom of this page, but not tonight.)
Thanks also to those of you who sent email to let me know you missed the images, and who did some helpful troubleshooting.
One of the great strengths of the web is the generosity of the people in its communities. I'm ever grateful for the kindness and support.