Answer to Question 1
Answer: Form refers to the overall structure of the work, including the materials used to make it, its various formal elements, and the way the elements are organized into a composition. Content is what the work of art expresses or means. Form can also suggest meaning.
Answer to Question 2
Answer: The mirror reflects the backs of the subjects and, standing in the same space as the viewer, are two other figures, one of whom is most likely the artist.