There are two major yellow curves that cross the center of the image, one plain, the other segmented into a yellow "dotted line", although perhaps "dashed line"

There are two major yellow curves that cross the center of the image, one plain, the other segmented into a yellow "dotted line", although perhaps "dashed line" is a better term for it. Follow this "dashed line" to very near the top right of the image, past the crab, to the place where it meets the border with white marble, and then just below that, on the marble border is the small square that is basically black.