[Plugin: Embed Facebook] vertical thumbnails stretched/skewed

This is working well for a site I have been working on, however some of the pictures are stretched, and I am wondering if there is a fix for this.

The vertical picture thumbnails are showing up the same size/shape as the horizontal thumbnails, which makes them skewed. When you click on them they open up looking normal, it’s just in the thumbnail.

Does anyone know a solution to this?
Thanks.

http://ww.wp.xz.cn/extend/plugins/embed-facebook/