As we know the lads' elders were crouched at the opposite end of the former sacrificial structure when before their eyes the lads were swallowed up - The Border Boys Across the Frontier by Fremont B. Deering

Assuming that we have before us a sacrificial ceremony and that the group was executed after the self devotion of Antinous had passed into the popular belief we may regard the elder youth as either the Genius of the Emperor separate in spirit from Hadrian himself and presiding over his destinies who accepts the offer of Antinous with solemn calmness suited to so great a gift or else as the Genius of the Roman people witnessing the same act in the same majestic spirit - Sketches and Studies in Italy and Greece, Vol III. by John Symonds