The narrow pictorial space and the closeness of the green curtain with the acidic yellow raking light doesn't leave him [Johann Friedrich] much scope. The embroidery on the doublet, the summary execution of the brown fur, the gold chains and the numerous rings illustrate his royal class, his gaze seeks allies and loyal subjects. [...] On this portrait the disfiguring scar on his face was considered disturbing and overpainted, but it is still visible.
[Löcher, in Cat. Schwäbisch Hall 2009, 83]