Open Graph (og:image) over HTTPS doesn’t work. Title, description, etc.. all load fine over HTTPS and Facebook respects 301 redirects so someone can mention vogogo.com or https://www.vogogo.com in their status and Facebook is able to pull the right content. At first I thought it was an image dimension problem. The Vogogo image used is 195:65 which is exactly 3:1, the ratio limit imposed on og:image images, so I loaded up some smaller images to test and the results were the same. Facebook tries to load the images but gives up. After some investigative work by Matt Warren and some subsequent Googling around it appears others are affected.
Moving the images to a non-HTTPS server solved the problem. The og:image tags aren’t loaded by browsers visiting the site so you don’t have to worry about people getting ‘insecure content being loaded over secure connection’ warning messages.