How to add images and directories already on server to Magento media browser list of images and directories?

I've installed a new Magento Store and just pasted a media directory from another Magento Store. But when I try to insert images to some page or product using the WYSIWYG editor, I can upload new images and create new directories, but the images and directories that were copied does not appears.

What do I have to do to programmatically add this images and directories copied to the list of the "Magento's media browser"?

Below follows an image in case I didn't make this question clear enough. (You may notice some white squares, I just made a quick edit in this picture to hide the directories and 开发者_JAVA技巧images, as I can't show them)