 Pictures of Cave Johnson , based on the face of lead animator Bill Fletcher , appear throughout Portal 2 . Though comparisons have been made between Johnson and Andrew Ryan , the wealthy industrialist who created the fictional underwater city of Rapture in BioShock , Wolpaw says the writers did not consider this character while creating Johnson . The two robotic characters provide some amusing death scenes in the cooperative mode , such as struggling while being crushed by a lowering ceiling . The artists thought the look of the robots would help tell the story , and the fact that they are holding hands emphasizes the cooperative mode . " Expressive noises " and mannerisms are used in place of distinguishable dialogue , and the robotic characters were designed as a double @-@ act , similar to Laurel and Hardy . 
