Synthetic observables of the cool, compact hybrid model HM I (left) and the more extended, hotter hybrid model HM II (right). From top to bottom: centre channel image, line-to-continuum flux ratio, characteristic size, and photocentre shift per velocity channel of the Brγ emission region. The ellipse depicted in the image signifies the half flux radius of the geometric Gaussian disk model used to derive the characteristic size. In the depiction of the photocenter shifts, the stellar rotational axis, not the north axis, is aligned with the vertical coordinate axis. The observational photocentres were rotated by −9° with respect to Fig. 1 to put them in the same frame of reference.