Hi again, Marcelo. I checked the Facebook share dialog both above and below your content on the linked page. The information does appear to be correct. Please, understand that our plugin has very little authority over the data that Facebook stores for a post. By default, our plugin does automatically set the og:image tag, but if you use a more expansive Open Graph plugin, you have the option to turn this feature off under Advanced Settings, but having more than one og:image defined does not cause any complications.
You can check your Open Graph definitions by opening the 'View Page Source' tool on any page and performing a search for og:. The og:image tag we set is commented with
<!-- Shareaholic Open Graph Tags -->
When new content is posted to the web, Facebook scans the URL and extracts data that it caches and uses to identify the content, some of which is seen when sharing or liking the page. If you ever run into a problem with what data is shown when using the Facebook share button in our plugin, open the content's permalink and check if the shared data matches what appears when using Facebook's official bookmarklet. The information should be exactly the same, because when you interact with our button, it redirects you to the same sharing submission form on Facebook's server where Facebook loads their cached data into the dialog (image, title, description).
Now, if the sharing information Facebook loads conflicts with the Open Graph data that appears in your page source, please run the URL through Facebook's Debugger Tool to force a new scan of your content so that any changes which have been made will be cached and applied during shares and to also check for any errors that need to be corrected in your Open Graph Meta Tags. This tends to be a quick way to resolve any Facebook-sharing issues.
Hope this helps!