.list {
    overflow: hidden;
    border: solid red 1px;
    padding: 16px;
    margin-right: 316px;
    }
    
.item {
    float: left;
    }
    
.item img.small {
    width: 100px;
    height: 100px;
    }
    
.item img.big {
    display: none;
    position: absolute;
    top: 50px;
    right: 0;
    width: 300px;
}

.item:hover img.big {
    display: block;
    }