How an XAP file can contain multiple languages

As you know, a WP app can contain multiple languages ​​when submitting an .XAP to WP Dev Center.

Now I have found MSDN and other docs, but never found that .XAP can contain multiple languages.

I'm building a WP VS2012 app and have selected multiple languages ​​on the page Supported Cultures

page Properties

, but when I submit it to WP Dev Center, it turns out that there is only English culture here.

How can I add multilingual support to my WP application?