It may be acquired at the auction during the quest Open Sesame!, either for 20 or 60 (only if you successfully got information from Yaromir and then told Vivaldi). If you gained the necessary information from Yaromir by correctly answering his question, buying the painting would later start the Avid Collector quest in which the painting can be sold on to Marcus T.K. Hodgson, a famed Novigrad book dealer, who will pay quite a tidy sum for it.
Associated quests Edit
- It's mentioned in the document List of objects in need of restoration found later on in the vault.