From Literary Terms and Definitions http://web.cn.edu/kwheeler/lit_terms_I.html
IMAGERY: A common term of variable meaning, imagery includes the “mental pictures” that readers experience with a passage of literature. It signifies all the sensory perceptions referred to in a poem, whether by literal description, allusion, simile, or metaphor. Imagery is not limited to visual imagery; it also includes auditory (sound), tactile (touch), thermal (heat and cold), olfactory (smell), gustatory (taste), and kinesthetic sensation (movement).
Read 2. Shakespeare: Sonnet 130 My Mistress Eyes (842)
and look at how imagery works in the poem. What sensory perceptions does the poet create? How does he/she use imagery to achieve meaning?