According to the author of the book, the verse describes how special decorations were made for big pillars in a beautiful building. These decorations included hundreds of pomegranate shapes to make the pillars look fancy and important.
2 Chronicles 4:13: And four hundred pomegranates on the two wreaths; two rows of pomegranates on each wreath, to cover the two pommels of the chapiters which [were] upon the pillars. [upon: Heb. upon the face of]
Specifies the number of pomegranates differently, potentially creating a variation in the temple description.
1 Kings 7:20: And the chapiters upon the two pillars [had pomegranates] also above, over against the belly which [was] by the network: and the pomegranates [were] two hundred in rows round about upon the other chapiter.