Why are several of the Tu-104’s cabin windows oddly positioned? The Tu-104 (the fourth jetliner to fly1 and the second to enter revenue service2) has a cabin-window layout that is... somewhat odd, to say the least.



From front to back:


What appears to be the second cabin window from the front (although, given how far forward it, and the window in front of it, are, I’m not sure that they are actually cabin windows; I’m not familiar with the location of the Tu-104’s cockpit bulkhead) is mounted so high on the side of the fuselage (the whole window is in the white region above the blue livery striping on the sides; in contrast, most of the Tu-104’s cabin windows are mounted near the middle of this blue band) that one would only ever be able to see the sky through it, unless something was going really wrong.  It and the one in front of it also appear to be slightly smaller than the windows further back, but this could just be perspective or a trick of the eye.
The two consecutive windows over the front middle section of the wing are mounted higher than the windows in front of and behind them, although not as high as the window discussed in point #1 (most of the area of these windows still falls within the blue area, with only the tops of the windows breaching the white).  The more forward of these two windows appears to form part of the second overwing escape hatch - but the window in front of it looks to be part of the forwardmost overwing exit, and, yet, is mounted at the normal height - and these two windows have Aeroflot’s winged hammer and sickle painted in the space underneath them - but I’m having a hard time believing that a simple livery detail would have any significant influence on the design of the aircraft itself (it’s usually the other way around!).
The fourth window from the rear is mounted about as high as the windows discussed in point #2.  It lies above the numeric portion of the aircraft’s tail number, but - again like with point #2 - I’m having great difficulty believing that the window placement was simpler to alter than the paint job.
Finally, the three rearmost cabin (I think?) windows are mounted very high on the fuselage - about as high as the window in point #1.  These three windows overlie the “CCCP” portion of the aircraft’s tail number (but, again, see points #2 and #3!).


Why the wonky window work?



1: ...preceded by the Comet, Jetliner, and Caravelle.

2: ...preceded only by the Comet.
I found a cutaway diagram of the Tu-104B. It appears that, at least on this model, some of the seats in the middle were raised a bit to perhaps accommodate some engine parts (there appears to be a label on the diagram which I can't quite read). The windows were raised correspondingly to match the seats. The mid-positioned one at the aft may have been placed there to match one in a door on the port side of the aircraft. The three high-positioned ones appear to be windows in the toilets (туале́ты).