  The Parton-Hadron-String-Dynamics (PHSD) transport model is used to study the
influence of the initial size of spatial fluctuations of the interacting system
on flow observables in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV for
different centralities. While the flow coefficients $v_2$, $v_3$, $v_4$ and
$v_5$ are reasonably described in comparison to the data from the ALICE
Collaboration for different centralities within the default setting, no
essential sensitivity is found with respect to the initial size of spatial
fluctuations even for very central collisions where the flow coefficients are
dominated by the size of initial state fluctuations. We attribute this lack of
sensitivity partly to the low interaction rate of the degrees-of-freedom in
this very early phase of order $\sim$ 0.3 fm/c which is also in common with the
weakly interacting color glass condensate (CGC) or glasma approach. Moreover,
since the event shape in the transverse plane is approximately the same for
different size of spatial fluctuations very similar eccentricities $\epsilon_n$
are transformed to roughly the same flow coefficients $v_n$ in momentum space.
