I really like this. The walls being discolored in places where posters/signs used to be is a good touch. The only complaint I'd have is that the two areas that I'm assuming are doors on the bottom half of the horizontal hall (where the mats are) could be indented like the entrances on the vertical hallway. You could also have different colored doormats to mix things up, but that may or may not make sense depending on what type of building this is. Something like a research facility or even a school would have everything be one color, whereas in an apartment building it would be up to each individual resident.
made the outside color darker to make your eyes focus on the floor
rotated the door mat at the bottom to match with the orientation of the door
made the stains on the wall's where posters once hanged more smudgy
removed the 6 from the wall and put it on the door (figured it was a sign but looked like a wall stain might be a removed sign?)
cleaned up a few loose pixels in the lower left of the void
Well thought out with the subtle attention to detail in here.
I agree that the fire extinguisher wouldn't be up high on a wall. Perhaps store it on the floor by the fire exit door. Another neat touch would be a red box for alarming a fire somewhere on the other end of the hallway... Not essential though, unless it's about a fire? Ha.
The green border at the top... What does that represent? I just find that confusing, when you have a yellow border that is similar on the walls below. Are they both supposed to be the top surface of the wall, i.e. top down? Just a minor observation.
Lastly, the lighting is top down on everything apart from the elevator. The base of the doors are darker. Not sure if flipping the doors vertically would fix it. From the current view, it could be mistaken for twin beds sandwiched together ha I mean that it the lightest of jokes.
I hope you can take constructive criticism. You've helped me massively. Just wanna push you to iron out the little differences to help improve your work.
Obviously take from my comments what applies.
Keep at it!
Thinking about it, lights reflect off metal, so the elevator doors technically look right. I think it's just the dark section at the base just appears a bit thick.
Managed to zoom in and noticed the wear on the floor at the top where the wood shows through. Could add some more of this detail to the vertical hallway, as in comparison, the vertical seems less messy.