It is not all in our mind

That people see left-right reversal in various mirror positions suggests to Corballis (2001) that the reversal is not due to any geometric relationship but rather to some cognitive disposition. It is argued here that though the spatial relationship between real-world enantiomorphs greatly vary, a viewer and her mirror counterpart are bound in a specific spatial relationship determined uniquely by mirror position. When that position optically reverses the transversal axis, the perception of left-right reversal has a straightforward, physical account. Thus, the locus of the puzzle is in the case in which that condition is not met, namely in a frontal view. In that view a viewer judges her image in the mirror not by its relationship with her facet which faces the mirror but rather with the putative image of the latter in a frontal encounter. That entails left-right reversal. The cognitive disposition account is argued to be incomplete and doubtfully more parsimonious.