Featured image shrinks on facebook share

Hi there,

I’m having problems showing the right images when i share my posts on facebook. The thing, for what i figured, is that facebook only consider images with more than 200px in each dimension for sharing.

I use images with 400×209 px but, when i use the facebook debuger, it says the featured image on that post has 300×156 px, when i have no picture with that size on my site.

This is what the facebook gets: <meta property=”og:image” content=”http://wtfvideos.biz/wp-content/uploads/devilbabyattack_400x209-300×156.jpg”/&gt;. The featured picture of that post is http://wtfvideos.biz/wp-content/uploads/devilbabyattack_400x209.jpg

This is the post link: http://wtfvideos.biz/devil-baby-attack/

Then i’ve tried images with 350×200, and the FB reads the right picture. So, for what i see, when i upload a image with 400×209 px, it automatically creates a thumbnail with 300×156, but when i use a picture with 350×200 it doesn’t?

This makes any sense? can you help me?

Thanks