It's definitely wrong. You may have never looked closely at the flag of the UK (the "Union flag", sometimes known as "the Union Jack"). If you do, you'll see that the flag does not have reflection symmetry due to the slight pinwheeling of the St Patrick's cross (red diagonal) and St Andrew's cross (white diagonal), technically the counterchange of saltires. Thus, there is a right side up. When statically displayed, the hoist is on the observer's left. To fly the flag correctly, the white of St Andrew is above the red of St Patrick in the upper hoist canton (the quarter at the top nearest to the flag-pole). This is expressed by the phrases wide white top and broad side up. Here is the right/wrong way displayed in a simple picture:

In this case, the wrong-way-up flag caused a small diplomatic incident at an Anglo-Chinese trade agreement being signed in London. Some of the British were upset by it; the reaction of the Chinese is not recorded.

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