If I go to Google Plus and share a link to a question here on a Stack Exchange site, then it works and I get a preview of the question page when I compose the Google Plus post. I'm talking about a post like this one, which links to
However, if I do the same with a direct link to an answer, then it doesn't work. An example is this post, where I tried to link to this answer:
That showed up as a simple link with no thumbnail from the site. Does anybody know why this is so? From looking at the site with
wget, both links redirect to the page with the full text.