You won’t find the word, “pouty” in the Affenpinscher’s AKC breed standard, but the wording leaves little doubt that it’s desirable. It does read, “Lips – Black, with prominent lower lip.”
This prominent lower lip lends much to the breed’s marvelous “monkey-like” expression which is created by a short muzzle, a longer and broad bottom jaw with no rise, and a slightly undershot bite. Note that a level bite is acceptable “if the monkey-like expression is maintained.” Understand that the dog’s face shouldn’t look like a monkey, but rather, remind us of one. Certainly, the dog’s attitude is part of the perception that this is a rascally breed, but without the “Affen expression” enhanced by a correct bottom lip, it may be an Affenpinscher, but one without type. Put another way, a 1959 Cadillac Coupe deVille without its iconic fins may technically be a Cadillac, but it just doesn’t look the same.
Neither is the Affenpinscher a brachycephalic breed. The nose, turned neither up nor down, is large with open nares.
By the way, did you know that the artist, Renoir, included an Affenpinscher in his famous “Luncheon of the Boating Party?” Most of the models in the painting were all friends of the artist, fitting as it was his last Impressionist masterpiece painted in 1881. See if you can find it.