Thanks for the comments,
@lazym13 I am unsure if the OP likes it, though because I left out lots of cables and other stuff out.
This is how I approached it:
1) Make a selection of the fireplace, TV the couches on Right, the sofa on Left,the walls on either sideand the roof - basically selected everything except for the wall. I included places under the TV. My selection looked like this:
2) I selected Refine Edge (Select and mask) and selected Output Settings as "New Layer With Layer Mask". Everything in white appears and everything in black is not seen. Essentially, the wall is not seen.
3) At this stage, I placed the marble brick pic UNDER the layer just made in the above step. This layer is sized appropriately and adjusted such that the top layer of bricks is fully visible. I applied Adjustment Layer of Brightness/Contrast and reduced brightness to suit the room.
4)Above this marble brick layer, I made two layers for shadows. One layer takes care of the lamp shadow to the Left, TV shadow and the wooden ledge shadow on either side. This layer is given sufficient Gaussian blur. Another shadow layer covers all corners where the new layer touches the old picture so that the layers appear to merge well.
If anything is unclear, please ask. I will be happy to try to explain better.