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
Not a TV screen or a laptop screen – it’s a needlepoint work.  It would look a bit like this, except with tigers and hunters on it instead of two women and some flowers: 
 
 The opening line paints an embroidered picture of a lush, colorful environment and of tigers, a majestic, strong, and respected creature.  The subject on the screen is critical in this poem as tigers are known for their beauty, great strength, and fearlessness. Their prancing across the screen shows that they’re lively and free. There is an implication that Aunt Jennifer wishes she could possess some of these qualities herself. 
 Denizens  refers to “an inhabitant or occupant of a particular place”.
Aunt Jennifers Tigers