Between the living room and the dining room we wanted to create a sense of separation yet still keep it open. On one side (the left) the elevator shaft juts into the space, so we just mirrored that same size on the other side (the window wall) and brought the ceiling down a bit overhead to give it a sense of compression, like it was supposed to be that way.
Here is the wall on the left:
It's not done yet, but so far we added a giant triptych of a sail boat, and my grandmother's table (which is dramatically under-scaled, I know). On the other side, we have "hidden doors".
As you can see there is a ton of electronic equipment. (One day I will organize all those wires, promise). We also store our folding chairs there for when we extend the dining table and need to seat 14, and our high chair for when babies come to visit (ours still needs to learn to sit up first before she will make use of it). This is also the spot with the cable box, the alarm controls, lighting control panel, and the phone/data panel for the entire house. It's a man's dream room. And it allows us to have this massive TV with no furniture under it, no wires and no boxes visible, something that both of us are happy about.