All images and transformed images are delivered by Cloudinary through a CDN with advanced caching for optimizing performance and improving the experience of your users. Images that were already available in your site, are cached in one or more CDN edges. Therefore, even if you delete the image from your Cloudinary account, cached copies might still be available. In default, all delivered images are cached for 30 days. This means that after that time all cached copies of deleted images would be removed from the CDN too.
In most cases, these behavior answers the requirements of web sites and mobile applications. Note that any public image might be have been also copied or cached by proxies, search engines, etc. It is in our roadmap to allow forcing immediate invalidation of cached CDN copies of deleted image using the Cloudinary API.