Why does Embedly choose the image that it does?

Embedly looks at the following attributes of the page and then ranks and scores the images.

• If the oEmbed type is photo the url of the oEmbed object
• The thumbnail_url of the oEmbed object if the oEmbed type is not photo
• The Open Graph og:image property
• The meta image_src tag.
• Any images found in the API response.
• Images ranked and pulled from the body of the page.

Read more about how Embedly chooses images: http://embed.ly/docs/response#images