In the context of La Bella, analyze the Interpretations of the History.
According to the general interpretation, della Rovere had seen the portrait during his visit to Titian's studio when it was almost finished. He commissioned Titian with works that were apparently related to this third-party commission. Based on similarities (as well as further letters and x-rays), "the others" / "gli altri" should be Titian's Girl in a Fur, Girl with Feathered Hat and Venus of Urbino.
By Moritz Thausing, La Bella was interpreted as a portrait of della Rovere's wife Eleonora Gonzaga, despite her youthful age. This interpretation is rejected nowadays, as the anonymous description "that woman in a blue dress" cannot be explained as being his wife.
By Leandro Ozzola, La Bella was published as Isabella d'Este, who is the mother of della Rovere's wife Eleonora (or his mother-in-law). Exactly matching in time, her commission to Titian for a rejuvenating ideal portrait after an older model by Francesco Francia (1511) is documented by Isabella d'Este. La Bella would fit this commission as an ideal beauty (with medium blonde hair), the date of receipt in Mantua (with high praise from Isabella) four weeks later would fit and also the anonymous description to his agent would be explained by the rejuvenation of his over 60-year-old mother-in-law. The commission of a "Resurrection" / "Resurectione" (for his wife) in this case becomes interpretable as an analogous rejuvenation of his wife. Rejuvenations/idealisations ("Resurectione" and "gli altri") would thus also be conceivable in Girl in a Fur (Eleonora Gonzaga?), Girl with Feather Hat and Venus of Urbino. This is indicated by x-rays that show, for example, for Girl in a Fur underpaintings with both La Bella and Titian's portrait Eleonora Gonzaga (c. 1537, Uffizi).However, Isabella's rejuvenating commission to Titian is claimed by the portrait Isabella in Black in the Kunsthistorisches Museum Vienna, which is considered doubtful (except its Viennese museum documentation). The eventual interpretation La Bella thus depends on the discussion Isabella in Black and "What is idealisation?", since naming the Viennese painting would neither conform to the ideal of beauty nor retain person characteristics (see other portraits of Isabella d'Este in the same museum).
Further attempts to interpret La Bella as a pin-up or courtesan fail because of the stringent portrait composition. And the only thing that really speaks against the noble lineage is the fact that Titian used her appearance in further paintings in which she was depicted in an increasingly erotic manner.
pin-up Eleonora Gonzaga Uffizi Girl in a Fur Kunsthistorisches Museum Titian Isabella in Black Isabella d'Este Kunsthistorisches Museum Vienna Francesco Francia Venus of Urbino Moritz Thausing courtesan