The 500 line segments defined above together form a shape in the Cartesian plane that resembles a bird with open wings. Looking at the line segments on the wings of the bird causes an optical illusion and may trick the viewer into thinking that the segments are curved lines. Therefore, the shape can also be considered as an optical artwork.[13][14][15][16][17] Another version of A Bird in Flight was defined as the union of all of the circles with center and radius , where , and
The set of the 20,001 circles defined above form a subset of the plane that resembles a flying bird. Although this version's equations are a lot more complicated than the version made of 500 segments, it has a better resemblance to a real flying bird. [18][19]
^"수학적 아름다움, 프랙털 아트의 세계" [Mathematical beauty, the world of fractal art]. Sciencetimes (in Korean). 8 December 2020. Archived from the original on 8 December 2020. Retrieved April 3, 2022.