Peter speaks of Jesus as if he were a shepherd who has authority over all other shepherds. This can be stated in active form. Alternate translation: "When Jesus, the Chief Shepherd, appears" or "When God reveals Jesus, the Chief Shepherd" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-activepassive]])
Here the word "crown" represents the reward that someone receives as a symbol of victory. The word "unfading" means that it is eternal. Alternate translation: "a glorious prize that will last forever" (See: [[rc://en/ta/man/translate/figs-metaphor]])