Which point do the eyes look at?
The third point from the top? The 4th one?
When the sight line is defined as a line connecting the centers of white eye and black eye, the eyes look at the top point (see below).
This optical illusion can be simplified as below.
See Akiyoshi's illusion page!http://www.psy.ritsumei.ac.jp/~akitaoka/friends8e.html
Citation: Watanabe illusion 2010, Eiji Watanabe (2010) https://doi.org/10.6084/m9.figshare.5838606