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If your subjects are privy to what you are doing you could also add a large neutral grey board with a high contrast focus target at the same distance  as your subjects that will be cut away from both images.  In the position of the other party or out of scene if you have enough margin to crop the outside. If you cannot let them know then you have to use a wall for exposure and the subject for focus setting.

You coax your camera to focus and exposure control onto the target. If you have the same lighting it should expose similarly.

For framing you use or prepare a set of sighting points like on a gun where you align the two points the same in both pictures.  A bottle of water or candle (anything really) that is there on both occasions in the same exact position on the table that aligns with a distant feature like the corner of the skirting boards in your example.  This will align the viewpoint if the furniture is in the same location (pencil marks on the floor for accuracy).

Also if this is not easy to repeat then I suggest you practice with stand in people until you are comfortable.

If you can get an actor to sit in the empty chair who will cast a credible shadow across the table when photographing the other person it will look more realistic.  You could also add a reflecting surface to catch the profile of your actor or else make sure there are NO reflecting surfaces if you have no actor.