Toy model of the inner disk region of GG Tau A including two illuminating sources. The left panel shows the radiation field generated by the two stars. For each star, the dotted contours mark the regions where the contribution from the other star to the total flux is 5, 10, and 20% (in red, the contribution from GG Tau Ab in the immediate surrounding of GG Tau Aa; in green, vice versa). The grey dashed line traces the contour where F_a equals F_b. The right panel maps the angles between the linear polarization vectors resulting from scatteringof light from Aa and Ab. In regions in which this angle becomes close to 90^o, PI could theoretically cancel out.