Mark it out with Rectangular Marquee Tool, make a copy of it (ctrl+c) and get back to the girl's file to insert it on a new layer (ctrl+v). Place it under the girl's layer and make the corrections of the size, using the combination Edit - Free Transform (ctrl+t). Then create a new layer: Layer - New - Layer and place it under all the previous layers. The last one should be painted in black color with Paint Bucket Tool.



Open now the picture of a window (ctrl+o).



Insert it above the background's layer. Because the picture is situated on a black background, it may be marked out with Rectangular Marquee Tool and not with Polygonal Lasso Tool specially.



Now we have to open in a new window the picture of tile floor, looking like a chess table. It maybe drawn for yourself also with Rectangular Tool and clicking on the shift button, then distorting it with Edit - Transform - Perspective and Edit - Free Transform (ctrl+t).



Insert it also on a new layer, above the window's layer. Don't forget to make the necessary corrections on its size and the distort level (ctrl+t).