When I look at my course feed, I see that the posts of some of my learners have the thumbnail image from the source page of the post.  But other posts appear to have random text in it and no image, even although the relevant thumbnail was properly set.

After feeding this back on the chat box, it transpires that the thumbnail is only included with the post if the said post came from the comments box at the bottom of the source page.  If the post came from a Post Text widget (or similar) as part of an activity, the image is replaced by a random clip of the text the learner actually posted.

This mixture of nice images (which, after all, have been carefully chosen by the author) and random clips of text look completely incongruous and ugly.

Could I respectfully recommend that all posts from whatever source have the thumbnail of the source page, so that the thing looks consistent?  Failing that, if it isn't possible to include a thumbnail if the post is from a widget, to just omit the thumbnail on those posts?