Wonderful Boston Neo-classical “composition work” mirror.  Possibly by John Doggett.
This mirror has the identical scene as the one in “American Furniture  - The Federal Period” in The Henry Francis du Pont Winterthur Museum by Charles F. Montgomery ( page 281 Plate 242).
Both figures in the tablet are inspired by popular portraits done by Adam Buck,  an Irish neo-classical portraitist and miniature painter principally active in London.

Completely original including tablet, mirror and back boards.
Cornice width = 25 1/2”