Step 1: Understanding the Poem:
The tigers function as a symbol of the freedom Aunt Jennifer herself cannot experience in her real life.
Step 2: Central Idea:
Rich critiques the institution of marriage as oppressive to women of her aunt's generation, while celebrating art as a space where suppressed desires for freedom and courage can still be given permanent, confident expression.
Final Answer:
The poem contrasts Aunt Jennifer's fear and submission in marriage with the proud, fearless tigers of her embroidery, suggesting that even though patriarchy can confine a woman's life, her creative expression can achieve a freedom and permanence that outlives her.