Image thumbnail on Facebook when liking a page
When people like a page on your website, you are able to control what image appears as the thumbnail on Facebook.
To do this, you need to add a piece of Meta Data code to the <head> tag of your page.The code looks like this:
<meta property="og:image" content="http://www.yourwebsite.com/uploads/sqrecipe/54/312_530x400_d99dcd230.jpeg" />
If an old image still appears after updating the above, you can go to the Facebook Debugger tool to try to fix the issue. Go here: https://developers.facebook.com/tools/debug and type in your page URL. This should clear the cache and show you the thumbnail that will be presented on Facebook. You should now see the new image that you set.
If you do not have access to the <head>, this alternative method also seems to work.
Add the following to your page:
<link rel="image_src" type="image/jpeg" href="http://www.yourwebsite.com/uploads/sqrecipe/54/312_530x400_d99dcd230.jpeg" />
I tested both ways and they both appeared to work correctly for me.