Schematic explanation of the effect of an excessive radial outflow velocity with fixed model aperture and inclination. The solid black lines define the outflowing cone aperture, the dotted black lines show the LOS directed towards the observer, and the grey dotted lines show the region containing the clouds with projected velocity within the v₁, v₉₉ observed boundaries. The grey clouds have LOS velocity above v₁, v₉₉, i.e. their weights are zero. Black arrows show the decomposition of the outflow velocity. The top panel shows the view from the top of the model, while the bottom panel shows the flattening effect as seen from the plane of the sky.