Image Properties Not Working

I have set the image properties field under Edit File Upload Preferences for a given upload destination as follows: class=”img-responsive center-block”

In the documentation it says:

These properties will be added inside the image tag (if an image is uploaded). Leave this setting blank if you do not wish for any properties to be added.

For example: If you have border=”0” alt=”image” name=”image” set as your preference, when you upload an image, the resulting tag will look like this:

http://example.com/images/upload/pic.jpg

However this is not working for me… any ideas?

Thanks!

Guy