People in the same setting tend to have simular faces and personaries. this is a trope for people in the same setting.the people can be friends ,emimes,etc.However they can be differened by hair, skin tone,body type.But the faces must be simular for this to quality.
Exemples:Big time rush:Kendall and James Played shant and subverted with Carlos and Logan.
South Park:Stan and Kyle Averted with Cartman and Kenny
Totally spies:Sam,Alex,Clover and Mandy