macOS 10.15.6 Photos stuck in "Analyzing Scenes"

Thanks for the idea of checking the Activity Monitor. Unfortunately, all 1,200 threads seem to jump every 5 seconds, so not sure if I'll be able to conclude if Photos is frozen, or waiting for an iCloud data packet transfer.

Meanwhile, I have learned that "Analyzing Scenes" can go on for days or weeks, without ever ending. Apparently it is just for displaying collages of photos, not doing anything to the photos themselves.