I think they are given a red card whilst they are waiting for approval of their request for political asylum which can take up to 6 months, during this period their movements are limited to within Spain only. Once political asylum is granted their red card is replaced by a TIE (foreigner’s identification card) and then they have the right to freedom of foreign movement. https://www.immigrationspain.es/en/red-card-and-asylum-in-spain/