Channel maps of the HDO(3_3,1–4_2,2) (upper panels) and CH₃CHO(18_0,18–17_0,17) E&A (lower panels) blue- and red-shifted (continuum-subtracted) emissions observed during ALMA Cycle 4 towards the HH 212 mm protostar. Each panel shows the emission integrated over a velocity interval of 1 km s⁻¹ shifted with respect to the systemic velocity (see the magenta channel, sampling the velocity between +1.5 km s⁻¹ and +2.5 km s⁻¹) by the value given in the upper right corner. The black cross (oriented to illustrate the direction of the SiO jet and consequently the equatorial plane, see Fig. 1) indicates the position of the protostar. The ellipse in all the leftmost panels shows the ALMA synthesised beam (HPBW): 0.′′15 ×0.′′12 (PA = –88°). First contours and steps correspond to 3σ (4.5 mJy beam⁻¹ km s⁻¹ for HDO and 3.0 mJy beam⁻¹ km s⁻¹ for CH₃CHO).