You are right that the Polish AF checkers differ from. The regulation no. 38 of the Chief of the General Staff of the Polish Army issued on December 1, 1918 said the PAF markings should be like the ones on the wing tops in the pic you posted. Below the scanned copy of the order.
However the order seems to be not followed too strictly. Also it should be taken into consideration that the planes were delivered to the CWL ( Centralne Warsztaty Lotnicze - Central Aviation Workshops ) as disassembled kites and the markings were applied before the final assembling. So all depened on the painter/painters and the setting aircraft sections for painting.
Thank you Pal. Here the CWL no. 002. Please notice the fuselage markings and the wing ones. Not only different but also the wing ones without the outline. What makes it more interesting, the starboard checkers are reversed comparing to the ones on the port wing.