It was a newbie mistake
Thanks for the reply, Jim. It was a newbie mistake...It turns out I had switched (although I swear the program did without me) to looking at the Testing Server view. I'd never seen that view before; I always have it on Remote Server view.
So if it's of use to anyone, the green/gray folders are Local, the red are Testing Server and the blue are Remote.
If one's Testing and Remote settings are the same, does it amount to the same thing to make changes on the Testing Server as it does to making changes on the Remote? Looks like that was the case for me. Before I realized that I was working on the Testing Server, I made changes to the site. Now that I switched back to working on the Remote, looks like the changes worked fine on the Remote (live) site--and worked fine according to a regular browser.