Definition of "incongruity"

I was told that the Australian Government had had to send my name to London before agreeing to my appointment. My credentials were actually addressed to Her Majesty, despite the fact that the Government of the United Kingdom had recognized the Chinese Communist regime in Peking as early as 1950. No one, however, seemed to notice the incongruity of such an arrangement.

1983, James C. H. Shen, “Rejoining the Government”, in Robert Myers, editor, The U.S. & Free China: How the U.S. Sold Out Its Ally‎, Washington, D.C.: Acropolis Books Ltd., page 42