A portrait must convey some nuances. Be it the "stress" of her face (one should wonder if really the "stress" is due to what the westerner would think it is due or to a casual occurrence of the moment, such as a headache or somebody shouting out of the door etc.), a rifle on the foot, a hat with a panache, some cigarette smoke etc. There's something true and something "created" in all portraits. A portrait is the art of conveying something which is not explicitly stated.

Yes the hidden message probably was: this town has become dangerous, people have rifles in their houses, criminality is high, life was better once.

How do you "convey" this set of ideas to an European audience? With an image which somehow tries to convey this message. An image that's potentially worth one thousand words, without those words be explicited in the image.
Pellegrin chose a "grim" high-contrast portrait of a man in a garage with his rifle. Subconsciously that might raise thoughts of "urban warfare", anarchic chaos. Rationally, it's a man with a rifle in a garage. Night atmosphera and lateral light might add to the "message". They are not false or right in their own principle. It's an image created to portray an idea.

When Karsh portrayed Churchill in lateral light and high contrast, with his serious expression, he certainly meant something like that, giving an idea of the damnation of power, so to speak. I'm sure Churchill might have been portrayed in the shade of a tree, sitting on the grass, with a white dress while sipping a glass of wine and smiling but that wouldn't have worked the same.

Some people is making polemics about which was Churchill's exact job description before being Prime Minister of an empire engaged in a bloody war. That's not the point. The point is that the portrait tries to convey an atmosphere, something that words don't express but the soul hopefully catches. The photographer tries to create those images that work more than words in expressing a situation. That sometimes involves "creating" the image not "capturing" it.

And I don't think at all that this portrait equals in power Karsh's portrait of Churchill.

Also I think that to an American audience somebody in a garage with a rifle is much more natural than to an European audience. An American would probably not get the "exceptionality" of the civilian in civilian dress with an assault rifle (or whatever it is) at his foot.

Now, you'd say: well that's America so it's not Rochester. Such a portrait might have been done anywhere in the US, even the most tranquil spot.
I agree, rationally.
But the image to the intended audience "speaks" about a degraded economy, a compromised security in the city. It's created and it's a way to tell one story in one image, that's all.