The symbology of the Mateo's choir responds to the need to preserve the sumptuousness of the exterior facades and the richness of the Portico of Glory inside the cathedral, while at the same time filling with splendor the place destined to the posts of spiritual government. Presented as “the temple inside the temple”, three facades and a vestibule make up the space flanked by the pillars of the central nave.
The external iconographic programme, which was visible to the faithful who heard Mass, combines reliefs of towers that continue the apocalyptic narrative of the Portico and evoke the new Jerusalem with its walls. Alternated with the towers, voluminous sculptures of prophets, evangelists and apostles are arranged inside arcades. Of the 32 figures that were in total, 30 have been preserved, however, their identification with specific characters is complex, since they do not carry any attribute that distinguishes them beyond the attitude with which they are depicted. As with the Elders of the Apocalypse in the portico, the figures are grouped in pairs through the dialogue of postures and gazes. In order there are prophets (Isaiah, Jeremiah, Ezekiel, Daniel, Hosea, Joel, Obadiah, Jonah, Micah, Nahun, Habakkuk, Haggai, Zechariah and Malachi), apostles (Saint Peter, Saint Paul, James the Greater, Saint John, Saint Andrew, Saint Philip, Saint Bartholomew, Saint Thomas, Saint Matthew, Saint James the Less, Saint Judas Thaddaeus and Saint Simon the Zealot) and the four evangelists.
The vestibule corresponds to the main façade and its ornamentation consists of representations of Old Testament figures (Moses, Aaron and Samuel) and the Kings of Judah (Saul, David and Solomon) on the sides, accompanying the episode of the Adoration of the Magi in the central tympanum, where the figure of the Virgin Mary stands out above the others, creating the only Marian motif of the entire cathedral.
The motifs carved in the interior combined fantasy and liturgy equally. On the columns separating the placards there is a group of beardless “young singers” combed with curls or braids. Some faces smile as they prepare to sing what, it is intuited, would be inscribed on the posters they hold. Finally, enclosed within the trebolada architecture that gives shape to the crestry are the mermaids and animals of the medieval bestiary (centaurs, basiliscos, eagles, dragons. . . ).