This picture represents genetic variation. Genetic variation is when there's organisms but some of them are different like in shape, color, or strength. These usually happens when there's a mutation within the genes.
This picture represents overproduction and the struggle for existence because as in the picture there's seven rats but only three bugs leaving four rats without food to eat. The rats overproduced leaving some to starve due to the low amount of food.
This picture represents differential survival and reproduction. In the picture of the phenotype of some rats is the body coloe which is green. Because they are green they are able to blend in and risk getting eaten by the hawks. The white rats are getting eaten because they stand out so the green rats will stay, but not the whites.
This visual represents changes in gene pool. Changes in gene pool is when some organisms who doesn't have the same beneficial advantages as others die out leaving the population with just those who have the beneficial advantage. Which in my picture is the green rats, leaving the white ones gone. This connects to Dawin's other point differential survival and reproduction. As the less advantage die, the more advantage organisms reproduce.