Very nice!
Would you mind giving me a step by step? [please ]
Well, that was pretty much the two steps. But in more detail (if I recall correctly):
(1) select a chunk of the wall on the right, copy and paste (ends up in a new layer)
(2) flip the chunk horizontally and align the lines in the wall (may need to rotate a little)
The chunk of wall is now blocking parts of the side wall and the baby (and the mom!) so
(3) create a layer mask for that layer and paint away parts of the chunk to bring back the baby and the wall.
Theoretically that's all you need to do. However, as you've seen the result looks a little un-natural... which I believe is due to the darkness of the arm, probably caused by the mom being there blocking light from the side and reflected from the back wall. So you could:
( 4a ) just lighten up those shadows until it looks better, which would probably work fine
or what I did, which was copy the edge of the other arm to get a clean arm/wall edge:
( 4b ) copy a chunk of the baby's other arm, copy/paste
( 5 ) flip horizontally, select all (of the chunk of arm), go "transform -> distort" and adjust the edge of arm from the sleeve to the wrist to match the other arm.
( 6 ) I think I had to adjust the color of the chunk of arm to match the skin (added a pinch of red, took out a pinch of blue).
( 7 ) layer mask, paint to mask and blend in to the other arm. The advantage here is that that edge already has wall behind it instead of striped-shirted mom so the masking can be much sloppier.
Sounds more complicated that it seemed when I was doing it, perhaps. But no cloning, which could cause inconsistent texture in that whole area. One potential issue, however, is that step (5) is a pretty significant distort, which may be a problem in your hi-res/large-print original. Could be some work to get the textures right...
I can send you the photoshop file if you want to see what I did with the layers...
j