Photoproduction of jets and the virtual structure of the photon

We compute the ratio between the direct and the resolved photon components of single jet and dijet production in $ep$ collisions for the kinematical range covered by the most recent ZEUS data. We analyse the phenomenological consequences of different models for the structure of virtual photons in these observables and compare them with the available data. We also comment on the correlation between the so called $x_{\gamma}^{obs}$ and the `true' $x_{\gamma}$, that can be inferred from the data.