The article deals with the evolution of such important aspect of Vladimir Nabokov’s individual style as image system. Navokov is much better known as prose writer. However, he began his creative career as a poet and continued to write verse all his life. The utilized traditional approach to the definition of image as a transfer of conceptual characteristics makes it possible to carry out quantitative analysis of the concepts used by the author and to compare their quantity in early and mature periods of creative activity. Multivariate discriminant analysis is used as a statistical method to differentiate between the periods simultaneously on the basis of a larger number of variables (frequencies of concepts in the function of source domain). The obtained results demonstrate that there are significant changes in the individual style of the poet, and, consequently, in his worldview. The obtained discriminant model, which includes eight characteristics (concepts marking style alteration), makes it possible to automatically attribute the text to the right period in 100% of cases. Qualitative analysis of changes in the frequencies of concepts reveals a complex polyphonic character of style alteration, which includes both the transition from complicated to simpler concepts and a change to more complex understanding of living beings.