If it's authentic and period, it looks like a drawing/sketch for the Napoleon medal signed by the man who designed the medals-- Duvivier. Of course, it could be that someone had the medal and completed a study of it, much as people draw the works of famous artists now as practice. So, you need to see if that is in fact the signature of Benjamin Duvivier. I would be curious what a good antique store would say about it-- and what its value is. The large frame, to me, indicates that someone who previously owned it felt it was (a) very old or (b) very valuable. It would be interesting to see if they were correct.
It was framed that way to draw attention to what otherwise is a very small, easy to miss across the room type of image.
http://www.jstor.org/pss/985522
Revolutionary-Era Medals
During the first years of the French Revolution, the production of medals-once a royal monopoly-enjoyed a renaissance. With the breakdown of royal authority, the number of workshops producing medals, jetons (small medals) and medallions (oversized medals) multiplied.
These medallions were designed not only by independent engravers seeking to establish their reputations, but also by former royal engravers, such as Benjamin Duvivier, who now turned their talents to the glorification of the French Revolution. Medals commemorated the great figures and events of the period. In the first years of the Revolution, for example, medals depicted Louis XVI as the restorer of the French Constitution and as a great supporter of reform, not as the tyrant worthy of death on the guillotine, his ultimate fate. Other medals were struck honoring Jean Sylvain Bailly, the Comte de Mirabeau, and the Marquis de Lafayette, among other great Revolutionary political figures. Medals were also struck to commemorate key events, such as the opening of the Estates-General.