How to render-print content type fields in an article?
ok, here is what I would do:


Create a subtheme as per this video, let's call it mytheme
Go to sites/all/themes/mytheme and create a file there called 

node--comments.tpl.php

Go to modules/node/node.tpl.php, open it and copy eveything inside
Paste that inside the node--comments.tpl.php that was created in second bullet
Inside the node--comments.tpl.php, substitute print render($content); with your code

&lt;div class="green-box-comment"&gt;
  &lt;?php print render($content['field_comment_1']);?&gt; 
  &lt;?php print render($content['field_comment_2']);?&gt;
&lt;/div&gt;
&lt;div class="green-box-images"&gt;
  &lt;?php print render($content['field_image_1']);?&gt; 
  &lt;?php print render($content['field_image_2']);?&gt;
&lt;/div&gt;  


The reason we subsitute print render($content); with your code is that your content-type has 4 fields and through your code you render all 4 of them one by one, so nothing is left for print render($content); to do.
Go to appearance, enable and set default mytheme
Lastly, clear cache to be sure all the changes are picked up (configuration -> development -> performance)   


In this way, I would achieve to have my styling changes in a subtheme. So anytime I want to change something I can do it there and it will override what would be shown by the base theme, without changing core. This is following Drupal's best practices and keep my styling seperate from core, which makes the site more robust and easily maintained (&amp; upgraded)

note: by creating the file node--comments.tpl.php and following these directions, you will just change the output of the custom content type called: comments, while leaving the rest of the nodes to be handled by the node.tpl.php, without interference.

P.S. you can do without step 1 and go straight to themes/bartik/templates (if bartik is your default theme), create there the node--comments.tpl.php and continue from there, and although this is faster, I think it is bad practice for the reasons explained above :)