The old kingdom
The imagery of the old kingdom is the reader's signal for understanding the long-standing reign of Fabrizio's family in that region. His kingdom is not lavish, but it is well decorated and lovely. The times are changing though, so his reign is also defined by imagery that points to the aging effects of time. His appearance celebrates his power and authority, and his kingdom is respected at the local level.
Italy and the imagery of progress
The imagery most closely related to the passage of time is the Italian army in full battle gear, standing on the edge of Fabrizio's kingdom. When they enter to demand his compliance and surrender, this is also imagery pointing to the futility of his efforts to resist. They bring progress and fortune to the kingdom that he was unable to bring them himself, so the people accept this sign of progress as a good thing, which is difficult for him to accept.
Images of authority
They offer Fabrizio a role in the Italian government, mostly for show, which might have led to a new kind of imagery, the imagery of Italian wealth and power. Undeniably, the Italian kingdom has more wealth than Fabrizio's small kingdom ever could have, but upon considering the offer, he denies it, accepting a new role as a normal person. He sacrifices the illusion of power, deciding that it would not be enough consolation for him.
The imagery of natural life
The nephew's life is defined by a different kind of imagery, one that Fabrizio already lived and learned. His nephew and daughter are rapt by the urgency of their instincts. They fall in love, they celebrate romance through sex, without caring about the way it might look socially, and they are excited about life, because their bodies are coming into their prime. These details form a kind of imagery that points to the natural arc of the human life through time. Fabrizio's death is also part of this imagery.