Final answer:
Shakespeare's Sonnet 2 uses military imagery to describe the impact of aging on physical beauty, with 'besiege thy brow' meaning wrinkles and 'dig deep trenches in thy beauty's field' referring to deep lines or grooves. 'Thy youth's proud livery' symbolizes youthful beauty that fades over time.
Step-by-step explanation:
William Shakespeare's Sonnet 2 explores the effects of time on beauty and youth through vivid imagery. The phrase "besiege thy brow" suggests the idea of wrinkles forming with age as if winters are attacking the person's forehead. Similarly, "dig deep trenches in thy beauty's field" further intensifies this imagery of aging, likening the lines on one's face to grooves or trenches made by time. Lastly, "thy youth's proud livery" symbolizes the beauty and splendor of youth that will eventually wear away and be of little value, akin to tattered clothing.