I suggest that the High Priest (in the figure) carried the Book Of Life on His chest. It was called “the breastplate of judgment” (Ex 28:15), and it contained the twelve stones. Those “…stones shall have the names of the sons of Israel, twelve according to their names, like the engravings of a signet; each one with its own name shall they be according to the twelve tribes” (28:21 NKJV.)
Of course those stones represent the 12 tribes (or divisions) of God’s people, but I suggest that we are to see in each of those stones the many members —
From Gospel Workers p.34.
“Of Aaron, the high priest of Israel, it is written, He “shall bear the names of the children of Israel in the breastplate of judgment upon his heart, when he goeth in unto the holy place, for a memorial before the Lord continually.” [Exodus 28:29.] What a beautiful and expressive figure this is of the unchanging love of Christ for His church! Our great High Priest, of whom Aaron was a type, bears His people upon His heart.”