"La Joconde" is the French name of the Mona Lisa, which like about half of the collections of the Louvre, is included in the database, as one of 295 items by (42 including 6 paintings), after, or connected with Leonardo da Vinci.
This quote translates as "Joconde (Giacondo) put up this twin bridge here for you, Sequana; you are able to speak of this priest with authority" or "in this you can swear that he was the bridge-builder", punning on two possible meanings of pontifex.
An opponent of Arianism, he served as archdeacon to Jucundus (in Italian, San Giocondo; in French, Saint Joconde), bishop of Aosta.