  Context. The fate of a massive star during the latest stages of its evolution
is highly dependent on its mass-loss rate/geometry and therefore knowing the
geometry of the circumstellar material close to the star and its surroundings
is crucial. Aims. We aim to study the nature (i.e. geometry, rates) of
mass-loss episodes. In this context, yellow hypergiants are great targets.
Methods. We analyse a large set of optical/near-infrared data, in spectroscopic
and photometric (X-shooter/VLT), spectropolarimetric (ISIS/WHT), and
interferometric GRAVITY-AMBER/VLTI) modes, toward the yellow hypergiant IRAS
17163-3907. We present the first model-independent reconstructed images of IRAS
17163-3907 at these wavelengths at milli-arcsecond scales. Lastly, we apply a
2D radiative transfer model to fit the dereddened photometry and the radial
profiles of published VISIR images at 8.59 {\mu}m, 11.85 {\mu}m and 12.81
{\mu}m simultaneously, adopting the revised Gaia distance (DR2). Results. The
interferometric observables around 2 {\mu}m show that the Br{\gamma} emission
is more extended and asymmetric than the Na i and the continuum emission. In
addition to the two known shells surrounding IRAS 17163-3907 we report on the
existence of a third hot inner shell with a maximum dynamical age of only 30
yr. Conclusions. The interpretation of the presence of Na i emission at closer
distances to the star compared to Br{\gamma} has been a challenge in various
studies. We argue that the presence of a pseudophotosphere is not needed, but
it is rather an optical depth effect. The three observed distinct mass-loss
episodes are characterised by different mass-loss rates and can inform the
theories on mass-loss mechanisms, which is a topic still under debate. We
discuss these in the context of photospheric pulsations and wind bi-stability
mechanisms.
