The date on the statue is generally put around 50 CE (during the reign of Claudius), though I've not come across any real evidence as to the sculptor. In his paper "Fuseli, Napoleon, and 'Themistocles at the Court of Admetus,'" Joseph Ruzicka analyzes the pose of the statue I assume you're talking about (this one, found in the Museo Gregoriano Profano).

The Roman emperors understood well the particular power and prestige of this pose, using it (or certain aspects of it) in their cult images (simulacrum). Particularly authoritative is the outstretched raised hand, for as Richard Brilliant has written,

Whether interpreted as a gesture of speech or command, its forceful projection from the cylindrical body has an authoritative character, welling from the power of the bearer's position. The gesture implies reception and obedience, and arises from a conditioned awareness of that likelihood.

Brilliant continued that the pose of holding a spear or staff with the arm almost vertical was the "standardized model of the military status symbol typical of the mature Julio-Claudian period."

The propagandistic value of this sculpture is in portraying an emperor who's physically and mentally fairly weak in a powerful light, as the IRL Claudius "was physically weak, inclined to twitch and stammer, and clearly unfit for the military demands of any public career," according to Goldsworthy's Augustus (439). He was generally able to make public appearances, but dressed in heavy layers, ostensibly in order to hide his appearance.

I'll leave the interpretation to you, because this is kind of a homework question, but apologies that no one got to this sooner! I hope this at least partially answers your question.