When you create a promotion in Cool Tabs, you can choose and include the messages that will show up on Facebook when your promotion or a participation in it is shared on this social network. You can do it from the "Go viral!" section while creating your campaign. You can also do it when you create the personalised messages in a personality test or quiz with or without points for right answers.
Nevertheless, if you modify any of these messages (title, text or image) once the campaign is already online and you try to share it on Facebook, you'll realise that the content that appears is the same as before you modified it. This is due to Facebook cache.
In order to show the new content as soon as possible, you must use Facebook Crawler, that you can access from this URL: https://developers.facebook.com/tools/debug/. You need to include the URL of your campaign and click on Crawl.
A new message will appear, saying that the url has already been shared on Facebook.
You must click on "Fetch new information" so Facebook shows the changes you've made asap.
Once updated, the information shown on Facebook when you share the link will be displayed as it follows: