The most common form of imagery in this poem is visual imagery, where the words in the poem invoke images in your mind that you can visualize, for example.
"On either side the river lie
Long fields of barley and of rye,
That clothe the wold and meet the sky;" (Tennyson)
"This poem starts off by giving a visual overview of the situation. The reader is shown the river and the road, and, far in the distance, the towers of Camelot."
It is easy to imagine the location described in the lines above. They also contain figures of speech or literary terms. The "wold" or the world is given human qualities, such as wearing clothes, so this is personification. What clothes the world are long fields of barley and rye.
There is also evidence in the poem of Auditory Imagery, where the words create the image of sounds. For example:
"As he rode down to Camelot.
From the bank and from the river
He flashed into the crystal mirror,
"Tirra lirra," by the river
Sang Sir Lancelot." (Tennyson)
When the Lady speaks, she is talking to no one, there is no one present, she speaks to her surroundings, this is a form of apostrophe, when you address something or someone who is not there.
"Or when the Moon was overhead,
Came two young lovers lately wed.
"I am half sick of shadows," said
The Lady of Shalott." (Tennyson)