Impact of finite-sized corrections on the mean structure functions computed according to our model. The domain of analysis is a circle of radius R. Both panels show the same data, in logarithmic or linear scales. The emissivity model is of type Xbeta with a core radius r_c = 400 kpc. The turbulent power spectrum has injection and dissipation scales L_inj and L_diss respectively. The thick dashed line is barely visible and shows the exact result obtained assuming an infinitely extended analysis domain. Points at large separations s are subject to slight numerical instabilities.