The early paintings, the majority of which are undated, were created by Schubert during his studies, in his first creative phase as a freelance artist and during his stay in Istanbul. They already clearly show the basic features of his artistic work: Individual figures are depicted standing in a space suggested by colour and objects or are embedded in fields of monochrome colour.

His early portraits and figure studies already express an existential disposition. The landscape paintings, composed of ordered areas of colour, can be interpreted as a painterly and formal rendering of personal impressions and experiences.