Hi Jason,
OK - I understand now
That is controlled by the template.css at line 54 - shown below...
.rotator-preview {
background:url("../images/showcase/showcase-preview.png") no-repeat scroll 0 0 transparent;
float:left;
height:200px;
margin-top:20px;
width:348px;
}
So you have two options - remove the background image from the code above or edit it from the source images so that the back image is removed but you still retain the border for the front image.
Hope this helps.