Wow, what a vastly inflated pixel equivalent! It would require resolving down very close to the wavelength of light. The clock face is about 50 pixels wide, and at that count the whole panorama would be about 1000 MP. And the clock crop is far from "pixel sharp"; I would estimate about half the linear pixel density is all the image detail warrants, so about 250 MP or less.
Still impressive, and I am always struck by the sharpness of Daguerreotypes when I get to see them in museums; they make the "negative-positive" processes of the same era look like a big sacrifice of quality for convenience.