Magneto-optic (MO) experimental and computational studies are reported on arrays of epitaxial Fe(001) microsquares. Measuring the transverse Kerr signal, in both reflected and diffracted spots, when the array is exposed to a rotating magnetic field allows the quantification of the magnetization inhomogeneties within the microsquares. The MO signal at diffracted spots is extremely sensitive to magnetization inhomogeneities, while working at a large constant field amplitude eliminates uncertainties due to domain-wall movements. The presence of anomalous peaks at the diffracted MO response is unambiguously assigned to the matching of inhomogeneities of the magnetization distribution to the corresponding pattern periodicity. Interaction between microsquares appears as a second-order effect.