The first picture can tell us how the slaves were tied to Europe in chains so to say. When the slaves were transported across the sea, they were often in chains and in poor conditions. It can also tell us how Africa was bound to America and Europe during the slave trade.
Another picture can tell us how Africa is being depleted of natural resources. You can see there is a lot of gold in America, this could be cotton, sugar etc .. which was sent back to Europe for gold and payments. It is gold in Europe because they got richer from this trade, the whole trade is based on eachother. Europe sends finished goods to africa and sells them, while they take slaves to America and puts them at plantations, and then get luxury goods back to Europa to sell them.
Colonialism was very popular because a mercantilist policy was pursued which meant that one should sell more than one bought. Therefore, colonies occupied so the european countries at a market to sell to. They needed luxury goods such as tobacco and sugar that were produced in America by the slaves. Getting these luxuary good was imporant for the trade in Europe.
