What I love about this pic is it gives us a new perspective on the inside of 278. This appears to be Houdini's office or library, but this shot shows us the reverse angle of more well known photos (like this). It also gives us a look out into the hallway and what appears to be at the stairway railing. With this we could potentially pinpoint the exact location of this pic and Houdini's office in the surviving house, if we could just get inside the darn place!
Perhaps Houdini is calling out to the current owner of 278 to let us have look?