Aunt Jennifer's tigers prance across a screen,
Bright topaz denizens of a world of green.
They do not fear the men beneath the tree;
They pace in sleek chivalric certainty.
Aunt Jennifer's fingers fluttering through her wool
Find even the ivory needle hard to pull.
The massive weight of Uncle's wedding band
Sits heavily upon Aunt Jennifer's hand.
When Aunt is dead, her terrified hands will lie
Still ringed with ordeals she was mastered by.
The wedding band is literally heavy and big. 
 The heaviness also seems symbolic of Uncle’s treatment toward Aunt Jennifer. He could be demanding, severe, violent, or oppressive. The speaker may not be speaking about the uncle directly but referring to Aunt Jennifer’s marriage as oppressive or suffocating.
Aunt Jennifers Tigers