From "new kingdom thutmose bust of nefertiti": what leads scholars to believe thutmose used this bust of nefertiti as a model for other representations of nefertiti?

The scholars were led to believe Thutmose used this bust as a model of representation since : The Bust's lack of finish. This was found in the artist's studio, this sculpture lacks the degree of finish and precious materials that were common to Egyptian royal sculpture. Clues supporting the idea that this bust was a model do not include the style or inscription.