Step 1: Feminist Themes. The poem uses Aunt Jennifer's art as a symbol of women's suppressed desires for freedom, strength, and independence.
Step 2: Symbolism of the Tigers. The tigers represent strength and vitality, qualities Aunt Jennifer herself yearns for but cannot attain due to her societal limitations.
Step 3: The contrast between reality and desire. The contrast between the vibrant tigers and Aunt Jennifer's own frailty illustrates the disconnect between her aspirations and her reality.
Final Answer: \[ \boxed{\text{The poem symbolizes Aunt Jennifer's suppressed desires for freedom and strength, contrasting her art with her constrained reality.}} \]