So you're writing a post and you've found a pic you want to embed,
In order to do this, click the icon shown below that looks like a camera;
Paste the URL to the image you'd like to embed (width and height are optional);
And that's it! Well done .
Dedicated to @Greatness in response to http://primeforums.net/Thread-March-2015-Posting-Comptetition-Upgrades-More?pid=474854#pid474854