To minimize the attrition imposed to air flow in a object surface, several forms called aerodynamic have been developed. This modern object design implies a minimum resistance to air flow turbulence in its surfaces.
In the present experiment the initial paper form imposes a more turbulent air flow, making it impossible to turn off the candle flame. As you change the paper disposition, the air flow becomes more and more stronger to the candle flame. This is due to the fact that the final paper disposition offers less resistance to air flow (object more aerodynamic). In the end of the paper rotation it is acquired the best aerodynamic form, turning off the candle flamee. Now you know why modern cars have round fronts with a narrower surface.