Final answer:
In the center of the center panel, Jesus is the figure shown dressed like a king with a papal crown, symbolizing his role as the Divine Judge and his royal status in Christian iconography.
Step-by-step explanation:
In the center of the center panel, the figure depicted as dressed like a king with the papal crown on his head and another crown at his feet is Jesus. This is consistent with traditional Christian iconography where Jesus is often shown in a regal status to symbolize his divine kingship and authority as the judge of the world, as seen in scenes like the Last Judgment. References to Christ enthroned and the details surrounding Him, such as holding a jeweled book of the Gospels and being flanked by angels, emphasize the importance of Christ's central role as the Divine Judge and the embodiment of the Word.