Why is Cupid in the statue with Caesar Augustus in the VP history card?

[Karen in CO]

We were reviewing the history cards yesterday and my dd3 took the Caesar Augustus card and hugged it. She it was her favorite because she loves his baby. I had not really noticed the "baby" before that had to look it up. The picture is of the statue called the Augustus of Prima Porta and the baby she loves in it is cupid. So somebody explain why Cupid was depicted in the statue with the Caesar?

Before you ask, I was reviewing with her sister, not her but she likes to be wherever we are.

[Trivium Academy]

Wouldn't Cupid be a sign of the mythology of the period? Just guessing...

and I think it's wonderful that she likes the card. :)

[KarenNC]

Looks like interpretations vary:

http://etext.virginia.edu/users/morford/augimage.html

The statue of Augustus from Livia's villa at Prima Porta is a marble copy of a bronze statue that celebrates the return in 20 BCE of the military standards captured by the Parthians in 53 after the defeat of Crassus at Carrhae. It was probably set up in 15 CE, the year after Augustus' death. It is 7 ft. (2.08 m.) tall (Augustus was 1.70 m., about 5'7") and shows him as a young man (perhaps on the model of Alexander the Great, who died when he was 33), in military uniform. He is barefoot (a sign of divine status) and Cupid (riding on a dolphin beside his right foot) reminds the viewer of Venus, the divine ancestress of the family of Augustus, the gens Iulia. Augustus holds a spear in his left hand, and his right hand is extended as he addresses his armies. His stance is that of the Doryphoros (spear-bearer) by the fifth century Greek sculptor, Polyclitus.

http://web.mit.edu/21h.402/www/primaporta/interpretations/cupid/
A small support at the base of the statue depicts Cupid riding a dolphin. The figure of Cupid could remind the viewer of Augustus' lineage connected to Venus through the Iulian line4. Others have proposed the figure of Cupid is based on the likeness of Gaius, Augustus' grandson born near the time of the retrieval of the Parthian standards. If the sculpture was constructed by Tiberius to assert his right to the empire, this would seem unlikely, as Gaius would already have died and Tiberius would not have wanted to suggest he was not the rightful heir of Augustus1. The dolphin may refer to the naval victory at Actium1. Others claim it is a reference to the birth of Venus, rising from sea2.

Also interesting is that the right hand of the original statue was never recovered and the current position is one designed by the restorer. There's a question as to whether it might have originally been holding a lance.
http://web.mit.edu/21h.402/www/primaporta/interpretations/hands/