CCC 1160 Christian iconography expresses in images the same Gospel message that Scripture communicates by words. Image and word illuminate each other:
We declare that we preserve intact all the written and unwritten traditions of the Church which have been entrusted to us. One of these traditions consists in the production of representational artwork, which accords with the history of the preaching of the Gospel. For it confirms that the incarnation of the Word of God was real and not imaginary, and to our benefit as well, for realities that illustrate each other undoubtedly reflect each other’s meaning.¹

1 Council of Nicaea II (787): COD 111.