Use absolute positioning to put two div
s in with top:0;left:0;
and bottom:0;right:0;
. Like this in your CSS:
#box{
position:relative;
/* your styles... */
}
#box:before,#box:after{
content:'';
position:absolute;
width:100px;height:50px;
}
#box:before{
top:0;left:0;
background:#0f0; /* you could put some kind of image here */
}
#box:after{
bottom:0;right:0;
background:#0f0; /* you could put some kind of image here */
}
See this JSFiddle for a working demo.