Maybe it’s something else then. I’d love it if you could share some more insight.
Here are two pages from the site, and if you inspect the images that populate, they appear to be images that have been resized by the plugin (since they’re named “…/384×256.jpg” or “…1350×900” for example.
It seems to me that if they were original image files (and not ones optimized by the plugin) they wouldn’t have those size designations on them, since none of the original images I uploaded do.
Thanks again. Not that I don’t like the plugin (speed is a lot faster!) it just might not be what I was expecting here.