If you havent already, Google the 'elements and principles of art' and keep them in the back of your mind as you create You are very very good no doubt, but keeping these things slightly in the back of your mind makes your work really "pop", where people cant put a finger on what makes it look great - thats when you know you've used the elements and principles well.
I would suggest, in that top corner, dont put in much detail what ever you put in there.. just something that is fairly basic with form, but which has shape that directs you towards the centre column (some pipe work perhaps?) that will "lead" the eye. Keep up the excellent work. The a/c unit does this well on the other wall.
If I was to be very picky, I would put something very small like a pencil, paper and sharpener on the desk closest to the viewer all juxtaposed..
in the new update of the project (which I'll post when I have it ready), I added a pencil sharpener and a scaler on the nearby table ... Very good article on "elements and principles of art", I'll keep that in mind every time you make a new design or composition ... Thanks for everything!