I want to post an apprequest to the friends of a user with a request-specific image/picture. Unfortunately, the apprequests do not seem to support any picture/image/attachement mechanism, and the standard application icon is not sufficient. Is there a solution for requests to add images, or do I have to use stream or feed instead?
You can not customize the image that appears in the apprequest - as you have stated it used the standard application image that was uploaded in the app's settings.
You can however choose a photo when using the Feed Dialog as well as other information such as the description, the name, the link and a caption as demonstrated below:
var obj = {
method: 'feed',
link: 'https://developers.facebook.com/docs/reference/dialogs/',
picture: 'http://fbrell.com/f8.jpg',
name: 'Facebook Dialogs',
caption: 'Reference Documentation',
description: 'Using Dialogs to interact with users.'
};
FB.ui(obj);