Thanks Barney,
A bit withholding on the 'rest' of the needed information, but I figured it out.
If I want any 'photos' I uploaded to the User/Library/Screensavers folder, I have to select Classic in the Sys Prefs>Desktop & Screen Saver>Screen Saver sidebar, which then allows you to choose a specific Folder as Source...which you can then choose a path to that Library/Screensaver folder.
NONE of the listed Screen Saver choices on the left sidebar are named 'display pictures,' or 'choose from a Photo Folder,' so it's a bit vague, and Barney could have fleshed out the instructions bit more. But apparently all those choices above Monterey are for some type of 'tiling' of photos from whatever Folder you choose.