The Moovly Marketplace contains additional objects and libraries that are not yet available in the Moovly Editor.  When you import an item, you will find it when you reopen the Editor, in a library called "Marketplace Items".  

If you already have an Editor window open and you import a Marketplace item in another browser window, you will have to refresh the libraries to view the new item under "Marketplace Items".  To refresh the libraries, click the Refresh Icon on the bottom left hand side of the Editor window: