Websites often update with new assets (HTML, CSS and images). When you make a new guide we (usually) automatically pick up the latest changes. If you see old images or page content it's likely that your developers are not following best practices regarding asset versioning (also know as asset fingerprinting). Asset versioning stops caching issues ensuring your customers get served the latest version every time they come to your website.
Fortunately you can tell Nickelled when you release a new version of your website. This will tell our system to make sure to download a fresh copy for your next guide.