lightgallery/scss/lg-medium-zoom.scss

.lg-medium-zoom-item {
    cursor: zoom-in;
}
.lg-medium-zoom {
    .lg-outer {
        cursor: zoom-out;
        // Set cursor grab while dragging
        &.lg-grab {
            img.lg-object {
                cursor: zoom-out;
            }
        }

        &.lg-grabbing {
            img.lg-object {
                cursor: zoom-out;
            }
        }
    }
}