  Unveiling the physics that governs the intertwining between the nanoscale
self-organization and the dynamics of insulator-to-metal transitions
(\textit{IMT}) is key for controlling on demand the ultrafast switching in
strongly correlated materials and nano-devices. A paradigmatic case is the
\textit{IMT} in V$_2$O$_3$, for which the mechanism that leads to the
nucleation and growth of metallic nano-droplets out of the supposedly
homogeneous Mott insulating phase is still a mystery.
  Here, we combine X-ray photoemission electron microscopy and ultrafast
non-equilibrium optical spectroscopy to investigate the early stage dynamics of
isolated metallic nano-droplets across the \textit{IMT} in V$_2$O$_3$ thin
films. Our experiments show that the low-temperature monoclinic
antiferromagnetic insulating phase is characterized by the spontaneous
formation of striped polydomains, with different lattice distortions. The
insulating domain boundaries accommodate the birth of metallic nano-droplets,
whose non-equilibrium expansion can be triggered by the photo-induced change of
the 3$d$-orbital occupation. We address the relation between the spontaneous
nanotexture of the Mott insulating phase in V$_2$O$_3$ and the timescale of the
metallic seeds growth. We speculate that the photoinduced metallic growth can
proceed along a non-thermal pathway in which the monoclinic lattice symmetry of
the insulating phase is partially retained.
