Upper left: surface brightness profile of NGC 7796-1, as measured by ellipse, if the position angle is allowed to vary. The two short-dashed lines indicate the two components of the exponential profiles. Lower left: the fourth harmonic cosine-term (B4) as defined by ellipse. Negative values indicate boxy isophotes. Upper right: position angle of the major axis. From north to east: positive, from north to west: negative. Note that isophotes have position angles similar to the axis connecting the nuclei A and B. At larger radii, the isophotes are determined by the tidal tails and the light of NGC 7796. Lower right: ellipticity. The variation at larger radii is due to the tidal tail and the neighbouring NGC 7796.