Final answer:
Leopold's 'shack' symbolizes brutality and exploitation in the Congo Free State under his cruel rule.
Step-by-step explanation:
Leopold's 'shack' has come to symbolize two things: brutality and exploitation.
In the Congo Free State, which was considered Leopold's personal possession, the people suffered immensely under the cruel rule. The intermediaries who extracted wealth from the state brutalized the Congolese people, causing widespread atrocities.
This symbolism serves as a reminder of the dark history of the region, where the population was cut in half and numerous vile acts were committed in the pursuit of personal enrichment.