Thanks! I actually just posted the link to the photos in the body of the message, and our new link expansion feature did the work. On sites like Facebook and Twitter, you only get one link expansion per post, but we decided to allow many. And you get to preview them before you post to see what they look like.
Personally, I don't like the way the text with the image number looks below them but we're refining as we go, so we'll see.