Wikipedia
Imaginifer
The imaginifer was one of the signiferi in a legion in the times of the Roman Empire, who carried the imago—the image—of the emperor.
The imaginifer was added to the ranks of the legions when the Imperial Cult was first established during the reign of Augustus. The imago was a three-dimensional portrait made from beaten metal. It was carried only in the leading cohort.
Museums - Grabstein 5 Imaginifer.jpg| Headstone of Aurelius Diogenes, with inscription D:M:AV(re)LIUS:DIOGENES:IMAGINIFER (To the spirits of the departed, Aurelius Diogenes, standard bearer).