Link Arrows

Is it possible to introduce a customised icon such as the giling and white ribbon as an icon to be added with the arrow on the thumbnail links to different pages if so how can this be achieved, can you help or point me in the direction please as I am not familiar with the content: attribute of the css in

.image-overlay.overlay-type-extern .image-overlay-inside:before {
content: “”;
font-family: “entypo-fontello”;
}
please see
http://www.psweb-test1.com/?page_id=3595 and hover over one of the thumbnails. Rather than an arrow I want to put a ribbon here

Many thanks
pete