Answer the following question in 3-4 complete sentences. On the left is a black and white image. The black space appears to be a vase, and the white space appears to be two people looking at each other. On the right is the same image, but the black and white spaces are inverted. Explain what you see in the image on the left, verses the image on the right. What a person sees when looking at the above two pictures depends on what concept?