About Facebook wide-image layout
Facebook chooses the layout according several internal parameters to maximize views, click-rate, etc.
There's no fixed rule.
However, there are several recommendations to fill:
- The aspect ratio is very specific: image widths need to be 1.91 times the height.
- For the News Feed, Facebook recommends thumbnail images of 400×209 pixels.
- Images that are smaller than these dimensions will be resized to either 154×154 or 90×90 pixels.
- On mobile, Facebook’s recommended image size is 560×292. Images smaller than this will be resized to 100×100 pixels.
About Links back to your site
There are several ways to submit infomation:
About Open Graph tags
You can add Open Graph tags to your page. In this way you can better define how Facebook "reads" the page.
About Open Graph actions
Also, if your are submitting Posts with an App, there are new Open Graph actions to describe how the content was generated (Facebook assigns more newsfeed space to user-generated media):
- Explicit Sharing action, it's used to mark your posts as shared explicitly by a user (requires Facebook approval)
- User Generated Photo action, to mark photos as user-generated E.g. selfies (requires Facebook approval)
References: