These are all effective in creating images in the poem and in establishing physical point of view.
He clasps the crag with crooked hands;
Close to the sun in lonely lands,
Ringed with the azure world, he stands.
The wrinkled sea beneath him crawls;
He watches from his mountain walls,
And like a thunderbolt he falls.
In the first stanza, the eagle is seen from an external point of view as he appears very high on the side of the mountain, surrounded by the open blue sky, near the sun and surrounded by natural wilderness. The image is one of majesty.
In the first two lines of the second stanza, the physical point of view shifts as the world below is seen from the eagle's point of view. His perch is so high above the earth that the ocean below him appears "wrinkled" as the waves move across it, and the force of the ocean is so diminished by distance that it seems only to "crawl." In the poem's concluding line, the physical point of view shifts once again as the viewer watches the eagle suddenly dive from his perch. The simile, "like a thunderbolt," has connotations of power and speed.
Through the imagery of the poem, Tennyson captures and conveys the magnificence of the solitary eagle, seemingly alone and free in the natural world.