Well, that was weird.
I posted that last image via MarsEdit.
In the mobile app, the code shows up by default and I have to use a ‘view site’ button to see the image.
On the site itself, the code showed up at first and shortly after a refresh, the photo showed up.
Not sure I’ve got this thing completely down yet. I do have some sample code to play with though, as long as I can find the old codes Flickr use to use. Right now they just offer an iframe link.