Pictavo will automatically assume that you'd like to view your pages in "spreads" to help you envision what your actual physical book is going to look like. Even though you're viewing a 'spread', pages will not be linked.
TO LINK PAGES:
If you'd like to link your pages to behave more like a 2-page 'layout', add any item to your page.
If you're adding a background, the contextual menu will immediately give you the option of linking using the icon circled below.
If you add an accent or text box, you'll need to drag the item close to the gutter to trigger the link icon to appear in your contextual menu.
TO UN-LINK PAGES:
If your spread already has a background, the BLUE link icon will be present in your menu that will appear if you click anywhere on either page. When the icon is blue, this means your pages are already linked and behaving like a spread. Click the icon and your pages will un-link.
If your spread is empty and you know you want to un-link the pages, drag anything onto the page anywhere and the BLUE link icon will be present in your menu. Blue means linked. Click the icon and your pages will un-link.
NOT SURE IF YOUR PAGES ARE LINKED?
If you aren't sure whether your pages are linked or not, look for the yellow bleed area down the center of your spread. If you can see the yellow area in your gutter, your spread is currently in single page format.