No party or political movement has a monopoly on patriotism. Any mainstream political party will want to do their best for their country even if the people has differing views on precisely what constitutes the "best". Indeed, I have no problem with any political party using national flags in their promotional material. But shame on those politicians who want to beat the drum of patriotism to drown out coverage of bad decisions and third rate government. Therefore shame on Andrea Leadsom.
There are great reasons to be patriotic about our nation: we are an open liberal democracy with a free media and relative limits on the powers of the executive. These are great characteristics to celebrate throughout the world. So Loathsome Leadsom's demands that the media should be more "patriotic" in their coverage of Brexit is anathema to traditional British values of free speech. The government should not be telling the media how to report anything. Instead, the media has a duty to challenge authority and inform the people, even mock those in power.
Politicians who equate loyalty to the government with patriotism are unfit to govern. Andrea Leadsom has demonstrated that she should not be in office.