Complex sentence: The family then eats a luxuriously catered meal, and goes about systematically destroying every possession in the house, but in an automatic and lifeless manner, with barely any speaking (as are almost all of their actions in the movie).
Split into simpler sentences: The family then eats a luxuriously catered meal, and goes about systematically destroying every possession in the house. However, it is done in an automatic and lifeless manner, with barely any speaking (as are almost all of their actions in the movie).