A plot device is an element introduced into a story solely to advance or resolve the plot of the story. In the hands of a skilled writer, the reader or viewer will not notice that the device is a construction of the author; it will seem to follow naturally from the setting or characters in the story.
How does the handkerchief further develop Desdemona’s character?
For Desdemona, the handkerchief, as his very first gift to her, is a symbol of her husband's love. She cherishes the item and bemoans its loss. None-the-less, she is ignorant (and who wouldn't be), as to the actions of other characters to make this very small item proof of her affair with another man. Desdemona is a complete innocent.... she wouldn't even have understood the repurcussions. Unfortunately, the handkerchief is her first and last exposure to treachery.... she learns too late, and the handkerchief is not only the source of her undoing, but the catalyst to her death.
Othello
