Facebook wall extension demo with 2nd layout (pic at left) and half photo size. For this demo comments author logo coming as a question sign because i used a old user token for specific reason, there is no problem when page token is used to display comments.
Click the following submit button to generate user/page access token entering your application id and secret key. Read documentation for all details. Make sure popup is enabled temporarily in your browsers(Chrome, Firefox) and facebook app id and secret key is correct.