woocommerce/plugins/woocommerce-admin/client/components/flag/style.scss

/** @format */
.woocommerce-flag {
	&.is-round {
		overflow: hidden;
		border-radius: 50%;

		img {
			width: auto;
			height: 100%;
		}
	}

	.woocommerce-flag__fallback {
		background: $core-grey-light-500;
	}
}