Mirror symmetry in nuclei, as manifest in the properties of corresponding levels and transitions in conjugate nuclei has been a subject of several elaborate experimental investigations. It is now generally considered that nuclear wave functions may consist of small yet finite admixtures of excited nucleon components. Inclusions of these components would result in transition strengths different for the corresponding transitions in nuclei, and thus would account for the departures from the predictions of charge symmetry hypothesis in the frame work of nucleons only degrees of freedom. Quantitative estimates for selected cases will be presented.