Gallery block larger for mobile

Site URL: https://www.thelivinghouse.co.uk/mini-living-details

We would like to make the gallery block displaying three images starting with ‘design dossier’ gallery larger as it’s quite small on mobile view compared to desktop. How can we make this larger for mobile? I’ve attached a screenshot. 

Try adding to Design > Custom CSS. You can adjust 150%

@media screen and (max-width:767px) {
[data-section-id="61f16e86ca2a991d8d863d5f"] .gallery-slideshow-item img {
    width: 150% !important;
    left: 50% !important;
    height: auto !important;
    transform: translateX(-50%);
}
}