Question: Does Greit say yes when Peiter asks her to marry him? I couldn't work this out.
Question: Why did Vermeer's wife call the painting obscene? I'm sure there's more than 1 interpretation of it.
Answer: As with most paintings, there are undoubtedly different interpretations - everyone has their own views. In the movie, Vermeer's wife felt that it was obscene - that's her interpretation. A number of art critics have commented on a 'subtle eroticism' in the painting, and this may be what is being alluded to, using Catherina to carry the message across. It's worth pointing out that a number of Vermeer experts have disagreed quite vehemently with the portrayal of Catherina in the film - surviving historical evidence would seem to indicate that Vermeer's marriage was a happy one.
Answer: Because her mouth was slightly open.
Answer: Because it was a picture of a servant.
Answer: Obviously, since she married him in the end.