Lots going on in that stamp. That is "Hispania" the national personification of Spain. She holds the "Codigo Civil" The civil code of Spain, with numerous amendments, still in force today. At her feet, is the fasces, a bundle of sticks and an axe, a sign of authority (including the sword she is holding) On her head, is the Laurel wreath, a sign of triumph.
On the arms of Spain, the little triangle down the bottom, holds the image of the Pomegranate, allegory of fruitfulness , life, regeneration, and marriage.