The portrait shows Dr. Hans von Brücke, then a student of medicine.
However, it was not the intention of Oesterreichische Nationalbank to select this portrait because the person itself was of any major importance. In these days the identities of the persons displayed on Austrian banknotes were even kept secret. The task of the artist (Prof. Sterrer) was just to work out a portrait showing an "ideal young man's head". He was free to select any model which he deemed suitable.
(Information given by Rudolf Richter, Salzburg - Specialist on Austrian paper money, July 2009)