.ui-rotatable-handle {
    height: 16px;
    width: 16px;
    cursor: pointer;
    background-image: url(rotate.png);
    background-size: 100%;
    left: -2px;
    bottom: -2px;
    display:    none;
}

.plate_mockup:hover .ui-rotatable-handle {
    display:        block;   
}