Sign out of iCloud in Monterey 12.6.2

I'd like to sign out of iCloud and back in again to see if this will make the shared photos in Photos actually, er, share.

There does not seem to be an option to sign out in /System Preferences, and despite the internet pretending I can click on my name to sign out, on my Monterey 12.6.2 running on a retina iMac, when I click on my name in System Preferences, the geniuses at Apple offer me an emoji, or nothing.

Does anybody know how to sign the World's Most Advanced Operating System out of the iCloud webspace to see if this methodology will make it actually work?

Ta