Africa Footstep Cartoon

Obviously, the main visual elements is a giant footstep on a black shape of Africa. The cartoon is trying to show that the Europeans really left there mark on Africa. The author does not seem to have an opinion on whether it is good or bad, just that they had huge impact and it can still be seen. Now it is not obvious that it the Europeans were the ones who made the impact but it was probably someone who had taken control of Africa at one point or another. Maybe this point could have been more clear, because it is not very obvious that somebody had made a impact/left there mark, and the cartoon could be misunderstood if one did not know about Imperialism. I mean to say that I interpreted this cartoon the way I did because I was learning about imperialism now, but if someone else interpreted this cartoon it could have been quite a bit difference. If the author really was trying to say what I thought he had to say, then he/she should have made it more clear.