Ca₂RuO_4, a strongly correlated metal oxide and Mott Insulator, exhibits an insulator to metal transition and a large structural distortion along the c-axis concurrently at 365K with a hysteresis of about 30K. In this study, we examine the temperature driven insulator-metal transition (IMT) in single crystals of Ca₂RuO₄ at the nanoscale with wavelengths ranging from 10 µm to 16 µm, where a strong phonon resonance characterizes the insulating phase. Through this study, we clearly resolve the phonon mode at 16 µm among insulating domains coexisting with the metallic phase, in accord with the far-field optical response of this material. We also resolve a novel pattern of striped phase coexistence emerging on the sub-micron scale that we attribute to the large strain induced by the structural difference between the metallic and insulating phases. We discuss how the development of this stripe pattern spontaneously minimizes strain energy within the crystal. Our interrogation of the metallic and phonon responses of these coexisting phases provides nano-imaging evidence that the temperature and current driven IMTs proceed through fundamentally different microscopic mechanisms.