Answer:In my opinion, the speaker of "Ode on a Grecian Urn" admires the immortality of the urn's subjects (and of the urn itself) even more than its beauty. With the same idea that a poem can make its subject eternal, this beautiful Grecian urn has the same ability for its subjects to live eternally as well.
In one of the rare uses of the exclamation point in English Literature, Keats shows that these lovers will always be both beautiful and in love. Their love achieves immortality. Further, the speaker hints that a love and a fair maiden cannot remain in that state for all time in real time.