<http://schema.org/primaryImageOfPage>
"http://media.treehugger.com/assets/images/2011/10/valentines-day-cupcake.jpg"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/slideshows/gift-guides/valentines-day-gift-guide-2011-sweet-on-earth/>