  The possible existence of a continuum encompassing the diversity of explosive
stellar deaths,ranging from ordinary SNe to relativistic hypernovae associated
with long duration GRBs, is under intense debate. In this context, SN2008D
associated with XT080109 could represent a paradigmatic case, since it might
exemplify a potential borderline event. The main aim is to infer geometric
information of SN2008D through the evolution of its linear optical
polarization. We also report the polarization evolution of SN2007uy, and
discuss the properties of the host ISM towards the XT. The final goal is to
compare the polarization properties, and hence the geometries of both SNe,
which shone contemporaneously in NGC2770. This fortunate coincidence brought us
the opportunity to observe both SNe simultaneously, and most importantly, with
identical instrumental setups. The observations span 74.9 days, starting 3.6
days after the XT and are distributed in 11 visits. In addition we performed
observations in the mm range in order to identify the dominant polarization. We
report positive linear polarization detections at several epochs for SN2008D at
a level of ~1% and at ~1.5% for SN2007uy. SN2007uy shows constant polarization,
which could be described by the host interstellar polarization plus a constant
eccentricity expansion on the sky plane. A statistical analysis of the
distribution of the SN2008D Stokes parametres suggests that it could show an
intrinsic variable polarization component. Assuming the SN2007uy polarization
is constant, we find that the evolution of the intrinsic SN2008D polarization
could be explained by an aspherical axisymmetric expansion with variable
eccentricity. We come to the same result even if we make no assumption on
SN2007uy, although at a lower significance level. We suggest that at least the
projected, if not the intrinsic, geometries of both SNe could differ.
