According to Otto Ertl, who painted the lüftlmalerei at Frillenseestraße 5 in 1995, the mural is an amalgam of the two men who own the building.  

The two hired him to paint a lüftlmalerei, but when they couldn’t agree on a picture, Ertl came up with a creative compromise.  Ertl suggested painting them both engaged in their favorite hobbies, to which they agreed.  So, despite the obvious temperature difference, Ertl painted the two doing what they separately loved — one playing ice hockey and the other fly fishing — together.¹