Right now, it’s not possible to delete the image cache for a site. There are limitations causing that to be the current case. If you want to “refresh” an image, you will need to change its file name. Adding random query arguments, commonly known as “cache busters,” will not work.
There are WordPress plugins that allow you to rename media files and thumbnails, like “Media File Renamer,” “Regenerate Thumbnails,” and so on. You may want to check those out. Note that this is not an endorsement of those plugins, and you will have to work with the relevant plugin support to resolve any issues you encounter using the plugin.
That said, we can also purge individual images from the CDN for you. You will need to send a direct link to the file(s) as it appears on your site. These will begin with i0.wp.com
, i1.wp.com
, i2.wp.com
or i3.wp.com
. Note that since images can only be purged manually by individual URLs, there is a limit to the number we can purge.