Por Microsoft :
Group Policy applies to the user or computer in a manner that depends on where both the user and the computer objects are located in Active Directory. However, in some cases, users may need policy applied to them based on the location of the computer object alone. You can use the Group Policy loopback feature to apply Group Policy Objects (GPOs) that depend only on which computer the user logs on to.
A própria configuração de política pode ser encontrada em Configuração do computador / Modelos de administrador / Sistema / Política de grupo / Política de auto-retorno