Display only one image on Multiple Files (v2021)

You may Inspect HTML element and add your own CSS styles.For example, in newer versions, only the first image is shown in the multi-column Card View (so do not just copy and paste, modify the style to suit your own case), the CSS style is like:

        .card .ew-images > *:not(:first-child) {
            display: none; // Only show the first image in cards
        }