The portrait depicts Marcin of Przesiońsko, who died during war against the Turks in 1635. He was portrayed in traditional convention: in professor's attire, but with the palm of martyrdom – a symbol of death for faith.
Józef Skrabski, "Portrait of Marcin of Przesiońsko", [in:] "The Sacred Lesser Poland Heritage", 2024, source: https://sdm.upjp2.edu.pl/en/works/portrait-of-marcin-of-przesionsko