Trifles deals with subtle actions, mundane details, psychology, subtext. What is not said is as important as what is said. Stage directions are very important.
1) We never see the crime scene.
2) We never meet the main characters, Mr. and Mrs. Wright.
3) The men never find a "smoking gun" or a motive for the murder.
The three most important stage directions are as follow:
(Hale goes outside. The Sheriff follows the County Attorney into the other room. Then Mrs. Hale rises, hands tight together, looking intensely at Mrs. Peters, whose eyes take a slow turn, finally meeting Mrs. Hale's. A moment Mrs. Hale holds her, then her own eyes point the way to where the box is concealed. Suddenly Mrs. Peters throws back quilt pieces and tries to put the box in the bag she is wearing. It is too big. She opens box, starts to take the bird out, cannot touch it, goes to pieces, stands there helpless. Sound of a knob turning in the other room. Mrs. Hale snatches the box and puts it in the pocket of her big coat. Enter County Attorney and Sheriff.)
MRS. PETERS (takes the bottle, looks about for something to wrap it in; takes petticoat from the clothes brought from the other room, very nervously begins winding this around the bottle.
(After she has said this, they look at each other, then start to glance back at the door. After an instant Mrs. Hale has pulled at a knot and ripped the sewing.)
These stage directions show that the women have decided to suppress the main pieces of evidence, namely the stitching on the quilt. They uncover that Minnie was so nervous and afraid of Mr. Wright's cruelty that it affected her domestic labor, right down to the way she stitched. God is in the details. The women, thus, form their own community against the men; their jury finds her "not guilty," and they hide the evidence to prevent her from going on trial to be found guilty by a male jury.