The Wikipedia entry on Mehoffer is here. A better, more comprehensive account is here in the form of exhibition notes on the Musée d'Orsay site. The latter link notes that he studied in Vienna and Paris as well as Kraków, and later was an active member of avant-garde Young Poland movement of around 1900.
The d'Orsay article's title labels Mehoffer as being a Symbolist, though scanning examples of his work suggests to me that his commitment to Symbolism was inconsistent at best.
Okay, this is Symbolist, and some call it pre-Surrealist.
Three paintings featuring the artist's wife, Jawidga.
Mehoffer designed a large number of stained glass windows.