Wanda is talking to Della about the new dress she purchased to wear to a dinner last week. Wanda is telling Della that the dress fit fine at the mall, but on the night she wanted to wear it, the dress was too short!
Wanda shows Della exactly how she reacted by signing put on the dress and then mirror. Wanda looks into the mirror and signs short on her legs, exactly on the spot where the dress comes to. Her facial expression is dumbfounded: open mouth and wide-eyed as she puts her hand on her forehead. Notice that Wanda doesn't sign any dialogue, only action.
You can use Constructed Action for any type of information — humorous, serious, or simply informative. As with Constructed Dialogue, Constructed Action takes some practice, but it will sharpen your signing prowess.