This is the set of sources I used to manipulate this entry.

Open a new file and set the dimension you mostly like, I chose a 2000/1628 72pp. 8 bit, then we will turn it to 16 bit once the job is over.

Make an accurate selection of 2 columns (crossbar included) and start to alter, distort, tilt, enlarge, and shrink every single column pair from the foreground toward the background, then fill the empty spaces and correct the curves with the clone tool

Select the wall, is not needed an accurate selection, the polygonal lazo tool is quite good. Make a copy of it, desaturate and set to multiply, Duplicate the original again and use: filter/high pass and set it to 3.2, then change the blending mode to overlay.

Added the Observer and changed the color to green, to emphasize it a little more, due the fact that we are going to place a black and white wall in front of him, used a curve layer to increase the contrast.

Add the chess texture wall, enlarge the prospective to give the sensation of depth, duplicate the layer and set it to multiply with a 75% of opacity. Then add a b&w layer on it.

now it's time to create the print which will turn into reality, deselect the colonnade layer (but use it often as a reference) add the Venice picture and begin to alter it by giving a wave shape (I used some of puppet warp too), use a layer mask to hide the parts we do not need to see, use the clone tool to reconstruct the spoiled parts (I used it too to remove the crowd on the bridge, to reconstruct the handrail, and to create a curve which will match with the steps (we will see it later). Therefore, make a copy of it and set it to soft light 29%, and finally, add a b&w layer and use a gradient on the layer mask to reduce the intensity and set the passage from b&w to color.

Took a selection of the pictures (just the inner part) and created a stroke with black. Distort and alter it too to fit it with the wall

Use the lazo tool to select the sidewalk, use perspective, distort and alter to give it a irregular shape. place it on the bottom of the layers palette. Duplicate the layer, desaturate and set to multiply 38%. Next, make a new copy and add again the high pass filter to overlay.

Make a selection of the steps and the columns. Set shrink it till it fits with the bridge on the background, add a levels layer to darken and contrast it a little bit.

Use the pen tool to make a selection of the lady and use the refine edge too on especially on the white hairs. Then place her on the sidewalk.

Duplicate the lady, set it to multiply 100% to take off all the hard lights on her

Desaturate everything within the gallery except the observer. I used a 40% opacity black brush on the observer layer mask to recover a little bit of saturation. Then add a new layer and name it shadow, set it to multiply place it beneath the observer and use a soft brush 72% of opacity to paint a shadow against the wall, is it is too much dark you can still reduce the opacity of the layer

Now to colorize the wall I used a color balance layer, click on mid tones and set: red 100%, green 72%, and blue 34%.

Add a cold photographic filter layer with a 18% of density

Added a shadow and use dodge and burn on the ladies to restore the lights on her

Create a new layer and set it under the colonnades, let's paint some shadows against the wall, the observer, and the prints. Then use dodge and burn to enhance the lights and the shadows on the columns, the wall, and the observer.

Add the texture and set it to overlay 48% of opacity. Add a new layer and fill it with black, then use an extra large eraser tool with a 50% of opacity to remove the black from the middle and the down-right side. Here we are. The job is done

The photo I took of a chessboard.