A tableau is a dramatic picture. If you catch a glance into the Oval Office and see top advisers speaking to each other with intensity, you behold a dramatic political tableau.
Tableau comes from the old French for "picture, or painted target." We usually use tableau to describe a vivid living scene. If you are a journalist and want to describe the tension in a courtroom, you might write a verbal tableau of the judge, the jury, and the witness box. People used to entertain themselves by doing tableau vivant, or living pictures, by reenacting perfectly the frozen scene of a famous painting.