I’ve just come across the same error.. It happens in any post I add a Jetpack slide show.
The slideshow looks to be working fine, i just have an error message across the top of the page:
Warning: Invalid argument supplied for foreach() in /misc/4/000/235/265/3/user/web/website.com/wp-content/plugins/jetpack/modules/publicize/enhanced-open-graph.php on line 49
