  The theoretical understanding of the nematic state of iron-based
superconductors and especially of FeSe is still a puzzling problem. Although a
number of experiments calls for a prominent role of local correlations and
place iron superconductors at the entrance of a Hund metal state, the effect of
the electronic correlations on the nematic state has been theoretically poorly
investigated. In this work we study the nematic phase of iron superconductors
accounting for local correlations, including the effect of the Hund's coupling.
We show that Hund's physics strongly affects the nematic properties of the
system. It severely constraints the precise nature of the feasible
orbital-ordered state and induces a differentiation in the effective masses of
the zx=yz orbitals in the nematic phase. The latter effect leads to distinctive
signatures in different experimental probes, so far overlooked in the
interpretation of experiments. As notable examples the splittings between zx
and yz bands at Gamma and M points are modified, with important consequences
for ARPES measurements.
