I have noticed lately that Casa dei Dioscuri seems to have some of the best paintings in Pompeii. Here is one in the third style (I will use one day next weekend to explain all these different styles).
Until then, notice how this painting depicts a building - it's not random geometrical shapes! We have two columns in the front that are supporting a wooden roof. In the background we see a fountain and a peacock. The setting kinda reminds me of this picture that I posted a while ago.