It's a narrow hallway, so I'd hang something on the wall to give it depth, like a painting showing distances, or a large black and white photo with that same theme. It would also be a great place for a wallpaper mural.

changing your paint to a semi gloss will help with lighting so will mirrors and taller baseboard will draw eyes down naturally

Thank you!

What if u hung family photos printed in black and white on one side (many of them placed in an orderly fashion) and the other side may be fully covered by mirrors so that the hall way would look more wider. With the existing floor tile, u may also think of changing the wall color to white.