What is the importance of Frenhofer's studio in the short-story, The Unknown Masterpiece?

Frenhofer’s studio is located some distance away from Porbus’s studio. Frenhofer’s home and studio are massive, reflecting his wealth. The house is full of paintings, both by Frenhofer and by other artists. However, his studio is kept barred from view, for it is where he works on his final masterpiece. Only later in the story is the studio gained access to, but then the focus is not on the studio, and only on the masterpiece.