The colorized B&W photo courtesy of ‘Page Siam Colorization by Noomrattana’ shows the winner of kite (= wow) festival at Sanum Luang in the reign of King Rama V (1868-1910). This type of kite is called wow Chula.
Note: the term ‘playing a kite’ means in Thai as ‘chug wow’ which can be used as a slang meaning ‘jerking off’.