.item-in .ms-img--dim-3by2:before {
    padding-top: 100%;
}
[class*="ms-img--dim"]:not(.ms-img--contain) img {
    width: auto;
    height: auto;
    min-height: auto !important; ;
    min-width: auto !important;
    max-width: 100% !important;
    max-height: 100% !important;
}