Ow can an art reveal truth?What kind of truth can art reveal?

For Visual arts and Philosophy class in university we need to submit short online comment, couple paragraphs long. The purpose of this assignment is to answer the questions: How can an art reveal truth? What kind of truth can art reveal?
Last class we discussed Heideggers comments on Van Goghs painting of the Peasants Shoes”. Heidegger says that Art can be a revealing of truth”. You can discuss assigned questions with reference to this work. The text(page 2) and the copy of Van Goths painting is in attachment. Or it would be much more interesting if you also could choose a different artwork to illustrate your point.

How can an art reveal truth? What kind of truth can art reveal?