It seems that your .slider-small-box element doesn't have enough width for the two images. It needs to have at least 540px width at the moment.
.slider-small-box {
/* was: width: 270px */
width: 540px;
height: 200px;
background-color: #eeeeee;
display: inline-block;
bottom: 0px;
right: 0px;
font-size: 0px;
line-height: 0px;
float: left;
overflow: hidden;
-webkit-box-shadow: 2px 2px 5px 0px rgba(50, 50, 50, 0.75);
-moz-box-shadow: 2px 2px 5px 0px rgba(50, 50, 50, 0.75);
box-shadow: 2px 2px 5px 0px rgba(50, 50, 50, 0.75);
border-radius: 5px;
}
Here's your updated fiddle: http://jsfiddle.net/JeVm3/1/