Application of a magnetic field offers an incisive opportunity to tune competing interactions in complex materials. Here we probe field-induced changes in the local structure of DyMn2O5 by using magnetoinfrared spectroscopy. The high tunability of the dielectric constant and ferroelectric polarization with field is well documented in the literature, but the lattice response on the microscopic level remains unknown. In this work, we reveal the dynamic nature of the local structural response to field and analyze it in terms of calculated mode displacements and local lattice distortions.