Schematic representation of the emitting components observed in the spectrum of I20210S: the high-velocity outflow (green shaded area) – assumed biconical for simplicity, since only one slit position is available and the PSF size prevents us from resolving the morphology of such a small structure – and the South Nebula (magenta solid ellipse), plotted on top of the PS1 grizy image of the galaxy. The slit position and orientation (white dot-dashed lines) are reported; in the upper left corner, the diameter of of the DOLoRes PSF (white dashed circle) is also indicated.