Mark it out with Polygonal Lasso Tool, make a copy of it (ctrl+c), place it on the layer above the girl, on the necessary place (ctrl+t) and copy two times this layer (ctrl+j). The size of the copies must be changed.



As not to lose our snails on this color gamma, we have to correct a little their colors (Selective Color), the brightness and the contrast: Image ? Adjustments ? Levels (ctrl+l).



As for the snails to look livelier, insert their shadows on the picture. But we need first to copy the layer (ctrl+j) and make it entirely black with the next command: Image ? Adjustments ? Brightness/Contrast.



Then place this layer under the basic layer with the snails and group it with that layer the girl is situated on: Layer ? Create Clipping Mask (ctrl+g). Distort it a little selecting next combination Edit ? Transform ? Distort.



Blur the shadow by applying the filter indicated here: Filter ? Blur ? Gaussian Blur.



Get back to the basic layer with the snails and apply on it another filter, for changing the lightness effects: Filter ? Render ? Lightness Effects.



And finally change a little the shadow's color, because we'll never have a totally black shadow: (Selective Color).