In my Tweak UI listing, the only item in Desktop is First Icon; Special Folders is in My Computer.
Through Tweak UI I relocated Desktop to D: I then created a new directory for My Pictures in Desktop and via Tweak UI relocated the Special Folder My Pictures to it. And, after rebooting, all is now exactly as I want it.
Many thanks, Stuart, for your patience in guiding me. I'm sure others will be interested in this solution.