Being rescooped means that a curator republished one of your articles on his topic. If your posts are frequently rescooped, it shows how relevant your content is and that you're also becoming a key pillar in your area of expertise.
The most interesting part of it is that it's a mean of reaching another audience, more potential readers. Indeed, as other articles, when you're rescooped, the title of the post links back to the original one located on your topic. Moreover, you appear as the discoverer of the gem on the other curator's topic. Everyone knows where the content comes from which will probably help you earn new followers.