The first 12 lines describe the painter's achievements. What are these excellences of Fra Pandolf's painting?
When evaluating the fictive Pandolf’s work, we must remember that we are seeing him through the jealous dismissive eyes of the Duke. “Busily a day” ... may be a clue to the hurried, uncomfortable mood of the live sitting. Pandolf’s work is excellent, lifelike, expressive – “as if alive.” That the painter is being flirtacious is ridiculous (he is a monk, after all), but that he has a good “easel-side manner” is borne out by his friendly remarks: “Paint must never hope to reproduce the faint half-flush that dies along her throat.” He is apparently a painter of note, since the Duke “drops” his name (as he does Claus of Innsbruck) to illustrate his own influence and power. Finally, the duchess must have admired the painter, judging from her thanks, again a source of jealousy in the Duke’s eyes.
The painter has managed to capture the essence of the duchess. The look on her face in the painting brings the speaker to relate her flirtatious nature to the audience in the following lines.