I just created a subdomain "up" to point to /wp-content/uploads and installed & activated the plugin. (My goal is to speed page loading time.)
Nothing has noticeably changed on the site though. The image files are still being served through the old domain & url. If I click on an image, I can manually change the url to use the new subdomain, and yes the image still loads, happily.
Just wondering what the next step might be if I want to have some or all of my blog posts point to the new subdomain for serving image files?
Does this plugin work "retroactively" or only for newly uploaded media?