1) Paper.li enables people to publish online newspapers from their favorite social media. An example is here : http://paper.li/tag/socialmedia. All the pages are provided in six languages (English, German, French, Spanish, Portuguese, Japanese).
2) For each of these pages, we are inserting OpenGraph meta information in the source of the page as described in Facebook documentation (https://developers.facebook.com/docs/opengraphprotocol/). We insert the following metas :
a. og:title : The paper title inserted by the user on our service.
b. og:description : A standard description for all pages on our service.
c. og:type : We do not used a standard type provided by Facebook here and we know that the page is classified in “Others” by providing the following value “paper_li:newspaper”.
d. og:url : This is the paper URL.
e. og:image : This is the image of the first article shown in the page to the user. (this is the most relevant content for this page).
f. og:site_name : This is top domain of the app, we mean here “paper.li”
g. fb:app_id : This is the Facebook Application Id we use for our service (providing a Facebook Tab App and login on our service too). This app can be accessed through the following URL on Facebook : http://www.facebook.com/362293833600.
h. og:locale : It defines the current language used by the user on our service
i. og:locale:alternate : It defines all the five other languages we support on our service
This meta information is working really well when using the send button or the like button with social plugins.
3) Our service provides papers who are updated every 24 hours on the same URL (each daily edition is served on one unique URL corresponding to the paper). By this, it means that “og:image” can change (that’s 99.9% of cases) daily, because first article fetched on the web will change daily and image too (corresponding to point 2.e). Paper title (indicated in OpenGraph meta by the point 2.a) can be changed by the user at any time too. In this example, the title is in Japanese in the Graph, for example, with always the same avatar picture in the wall posts.
4) As it’s suggested in your documentation, we want to use the publishing functionality from Facebook linked with the “Like” button. By this, it means that every time a paper is updated on our service, our service is publishing automatically a status to the page corresponding on the Graph on Facebook with the daily headlines (article title, description and image) through the GraphAPI. By doing this, every user having liked the page with the “Like” button will get the status in his news feed if Facebook decides to show it. That’s the purpose of the “Like” button and it’s working really well.
The problem is the following: when we access each of these pages liked on Facebook as an administrator (with application authentication token), we can publish statuses (what we are already doing), but they are published with a page avatar corresponding to the first “og:image” meta that was fetched by Facebook at the first “Like” of this page. It means users are seeing an image for this page that is not corresponding to the content (statuses) published by the page. Same problem appears with the title (if a user is changing it on our side, it can’t be updated on Facebook).
We find it very strange as for standard pages (created by “Create a page” button on Facebook), an access to “Profile picture” and page settings is provided as we don’t have it for pages created through the “Like” button plugin placed on our website (even if we are admin of the page through the app_id). The only way for us to change it for future pages is to change “og:image” meta information but it means that no more relevant image will be shared with corresponding URL (when sharing it in a status at a specific time, for example).
In conclusion, our question is the following: Is it possible to change avatar image and settings (title, ..) on Facebook (through Graph API) of a page created (in the Graph) through the “Like” button plugin? What would be the impact of this action?
No, pages cannot be created via the Like plugin. But if you're referring to a feed post being created, then still no because your app did not insert it.
If any authenticated app can change people's posts, regardless of which app created the posting, to their feed, then it might lead to abuse of the system.