I guess the Union Flag commemorates Capt. Cook's visit in the 1770's. Too bad the flag designers included the Red Cross of St. Patrick. That was not in the Union Flag at the time of Cook's visit. It is a nice anachronism, however.
Really, it is a nice looking flag and does not violate any of the rules of what make a good flag.
(2 voted this helpful, 0 funny and 1 agree)