During the creation of the site you have connected a social network. Initially you can choose only one for creating the site. If you choose to link a Facebook Page you will be asked the access to your profile only import the contents from the page.
Swite gives you the ability to connect other social and import content from them. From Social Network page at the top of the navigation bar you can connect other social networks.
Clicking on the Connect button will open a window where you can log in to the social and allow Swite to import the contents.
You can link only one social account per type. So if you have already connected a Facebook Page you can not connect another one. But you can always decide to create a new site for the other page.