Chemical contamination is when chemicals from industries or harmful sprays in farming get washed off into bodies of water.
What is the artist trying to communicate?
Amber finds this terribly difficult, which demonstrates the importance of binocular cues. Binocular cues are cues taken in by two eyes (binocular), versus one eye (monocular). This means that the brain is able to construct a three-dimensional interpretation of the world (by collecting information from the right and left eyes and then integrating the obtained information).