How does the author use metaphor in the poem, To Althea, From Prison?

Lovelace uses a variety of metaphors to explore what freedom is like. He compares his own freedom in his love for Althea, in the pleasure he takes in her company, in his freedom to speak, and in his love for the king, to a variety of imagined figures. Not the gods, nor the fish in the sea, nor the winds, but only the angels above, have a comparable liberty to himself, even in his literally imprisoned state. This sequence of metaphors calls on sensory and natural images of freedom. The sea and the wind are natural forces that move of their own volition, and which quite literally cannot be tamed or imprisoned. The speaker, meanwhile, very much can be. He is locked behind prison gates, without any of the freedom to control his own movement throughout the world that these natural forces might be said to enjoy.