I'm surprised how on discussions about the 'butterfly ballot', the impact of the viewing angle is rarely mentioned. See these images [1][2][3] that show that as the viewing angle deviates further from top-down, the recessed spine that holds the circular marks to be punched gets misaligned from the arrows that are supposed to be pointing to the proper spot.
As the ballot was installed on a stand at approximately chest-height [4] (it's really hard to find a picture of a person standing at it -- does anyone have one?), shorter people had a more oblique view making the arrows more likely to get misaligned.
As the ballot was installed on a stand at approximately chest-height [4] (it's really hard to find a picture of a person standing at it -- does anyone have one?), shorter people had a more oblique view making the arrows more likely to get misaligned.
[1] http://www.washington.edu/news/files/2016/03/3479146036_dda3... [2] https://c2.staticflickr.com/6/5291/5481639542_1e342a5f69_b.j... [3] https://upload.wikimedia.org/wikipedia/commons/0/06/Butterfl... [4] http://i.ebayimg.com/images/g/~jcAAOSw~bFWOQO0/s-l1600.jpg