By removing all previous repaints - contrary to Italian "good practice" - she has severed the historical continuity of the mural. By any standards, this was an act of extraordinary presumption.
Her action is defended on spurious grounds. Centuries of grime and repaint were said to be covering and "eating away" at Leonardo's paint. In fact, his paint survives on only 25 per cent or so of the surface. Moreover, it was last restored only 25 years before Brambilla began - by her teacher Mauro Pelliccioli.
After first setting the surface solid with English shellac, he scraped off all repaints except those that covered only bare wall. This was judged by Berenson to be a miraculous recovery: "I felt that I was looking at what Leonardo had painted, deteriorated by the centuries but no longer deturpated by incompetent hands". Brambilla has "recovered" not Leonardo but bare wall. As a result, the surviving islands of original paint have been reset in a sea of Brambilla's late-20th-century interpretative painting.
Tragically, in these terms also, her intervention fails. Her painting is simply not good enough. Her draughtsmanship is manifestly and painfully inadequate, and nowhere more so than in the reconstruction of Leonardo's crucially expressive hands.
In the redrawn left hand of St Jude, the tip of the third finger now contains four patches of blue pigment formerly belonging to the cloak of St Matthew. Ms Brambilla claims that "art professionals" have been "impressed" by her work. Would any of them care to defend St Jude's now-blue finger? Brambilla demands a "loyal" polemic.
It is her misfortune that most informed observers feel a greater loyalty to Leonardo thanto his successive would-be "interpreters".