This political cartoon represents the scramble for Africa. Africa has many natural resources. Back then, natural resources were very useful because not many things were invented. The entire reason for Imperialism is to find natural resources.
This also shows the wealth of the other countries. This is represented by there being a empty hole with nothing in it, and all its resources in other countries. Even though the supplies are originally from Africa, they get no benefit. This shows that all of the money that is supposed to go to Africa, goes to European countries.