kollapsminoriteten/wp-content/plugins/jetpack/modules/widgets/gallery/css/admin.css

.gallery-widget-thumbs-wrapper {
	margin: -5px 0 0.3em 0;
}

.gallery-widget-thumbs img {
	border: 1px solid #ccc;
	padding: 2px;
	background-color: #fff;
	margin: 0 5px 5px 0;
	float: left;
}