A moment of serenity

you see, there are certain rules when we’re talking about perspective and it’s included in an artwork. firstly, you completely ignored the perspective lines above their heads that clearly show us that this is not a parallel perspective, therefore, every single parallel (the floor line, the ceiling line - every single horizontal line with another horizontal line (same with vertical lines), to make it easier to explain), if put into a perspective, meets its “sisters” at the so-called “vanising point”. all the vanishing points are very easy to find: they are always situated on the horizon line and all you have to do is to connect two (or more, as you wish) lines that you know are parallel, but(!) one has to be above the horizon line and the second one should be below it. the point they meet at is called the “vanishing point”

judging by their anatomy, they are indeed standing in one straight (or very close to that) line: their heads and arms are the same size, but fedya’s elbows, shoulders and his crotch are situated just a littttle bit lower than dazai’s (the difference is equal btw). this gives us proof that (following the rule of the parallel lines under perspective) fedya stands closer to us (the viewer), therefore, if this small perspective was not present and everything was parallel, the difference between their heights would be even more noticable