It appears that the theme is built in. To use it, you need to include the singleItem
parameter in the initialization:
$(document).ready(function() {
$("#owl-demo").owlCarousel({
navigation : true, // Show next and prev buttons
slideSpeed : 300,
paginationSpeed : 400,
singleItem:true
});
});
The site also includes this CSS which appears to make the images fill the container:
#owl-demo .item img{
display: block;
width: 100%;
height: auto;
}