Sketch (not to scale) of the model considered in this work. The primary is located at (0,0) and the secondary at (D,0). The dashed line represents the contact discontinuity (CD) and, on either side, the shocked winds S1 and S2 are shown. The two solid lines with arrows entering the WCR from both sides are representative of the different streamlines that make up the emitter. Photons produced in the WCR travel towards the observer through the unshocked stellar winds.