CSS is probably the best solution as most plugin tabs don't allow fields on them so you wouldn't be able to use a delimiter field. Below is an example of how to add an image to every tab (using your above site as example).
Code:
.cbProfile .tab-pane .tab-page .tab-content:before {
background-color: red;
display: block;
height: 50px;
content: "";
margin: 10px;
}
You'll notice with the above at the top of every tab will be a red block. You can change background-color to background-image, etc.. and supply whatever image you like there.
Another create thing is is you can have a unique background using this CSS at the top of every tab based off the tab simply by using the tab id instead of the generic class. For example the below will only add to the "Request Information" tab using its tab id.
Code:
.cbProfile .tab-pane .tab-page #cb_tabid_52:before {
background-color: red;
display: block;
height: 50px;
content: "";
margin: 10px;
}
You're basically replacing ".tab-content" with "#cb_tabid_52" where "52" is the tab id.