Resources are binary content, such as images, PDFs, CSS and textual sources such JS files, etc. It is important to remember that the content of these resources is not extracted for translation, so you have to translate / edit them separately.
When you open this screen, a subset of all Resources collected during a previous crawl will be listed. Scroll down to load more, or use the search field for lookup (as some websites are quite Resource-heavy, the search function is recommended).
Hover and click over any Resource to display a localization dialog for it. You can click on the green “plus” icon to mark the Resource as translatable. After doing so, a few fields will be added to the dialog: a source and a target language text box you can use to transcribe the Resrouce, and a target URL field which will contain the the URL of the localized Resource on the proxy. Use the “Choose File” button to upload a localized Resource.
Note that you can only localize Resources one at a time and on a strictly target language basis (make sure you have the appropriate target language selected on the left side of the screen).
You can click on the flags on the lower left side of the frame to check the localized and original versions of a Resource (especially images, which will be displayed within the dialog). Document browsing, however, is not supported on the Resources screen.