This self-portrait displays a very different sensibility than those of the previous decade which show him in elaborate costume, posing and posturing for the public. If they were very much external portraits, this is much more a description of the man within. Adorned in plain working clothes he sits intently studying his own reflection in a mirror in order to capture it on a copper plate. He holds an etching needle in his right hand and the plate, unseen by the viewer, sits on a folded cloth supported on two thick books. The architecture is indeterminate, and the window serves only to throw a strong oblique light on his features, enhancing the mood of introspection. He seems to be saying to himself as much as the viewer: This is who I am, this is what I do.
An interesting detail is the strip of cloth hanging from the top of the window bearing Rembrandt's signature, added in the second state, and shaded (as here) in the fourth. A drawing now in Oxford (Benesch 1973) shows a similar device being used to modify the light entering Rembrandt's studio.