Sharing to Facebook etc doesn't share correct image.
When paging through a picture gallery, the code does not change the page level meta attributes.
This means that facebook gets the original page image (eg the WordPress Featured image) from the meta and not the image the user is trying to share.
<meta property="og:image" content="">
<meta property="og:image:width" content="">
<meta property="og:image:height" content="">
<meta name="twitter:image" content="">
This might need to be done on the server, the add-in would need to set the featured image based on the &gid=psgal_280_2&pid=1 query string, since when facebook etc calls the site looking for the image for the post it's probably going for the meta directly without triggering the javascript.
While this doesn't work, the sharing should perhaps be disabled...