We will need a steam for the apple and I decided to use the one from the left apple. The reason for that is that the steam from the middle apple it's too short and thin and it won't look good. So go ahead and make a selection of the stem from the left apple using the Pen Tool or your favorite selection tool (to make a selection with the Pen Tool first create your path than press Ctrl + Enter to transform that path into a selection).
Press Ctrl + Shift + C to copy merged and Ctrl + V to paste. Move the newly created layer above all layers and use the Free Transform to position it on the middle apple. You can also use the Warp tool to make look a bit different from the stem on the left apple.
Now for the tricky part. Because this is a metal ball it should also reflect the apples on the left and right. In order to create this reflection use the Pen Tool to create a selection of the left half of the right apple.
Press Ctrl + Shift + C to copy merged and Ctrl + V to paste . Now use the Free Transform tool and warp to position and tweak the appearance of the half apple to make it look proper on the metal apple.
Add a layer mask to this twisted half apple by choosing Layer > Layer Mask > Reveal All and fill the mask with black (click on it than press D to set default color and Ctrl + Backspace to fill with background color) and notice how all the pixels disappear. But we want to get rid only of the pixels outside the metal apple so what do we do? Well, we Ctrl-click on the metal apple to load it as a selection and then we click back in the layer mask. With white as foreground color press Alt + Backspace to fill the selection with white and thus reveal pixels only inside the metal apple. Looks good but I am not very happy about the way the bottom part looks so select a round soft brush and paint with black to hide the bad spot.
It looks a bit light so let's add a clip Curves Adjustment Layer mask to it. Drag the curve downwards to darken. Also, add a Hue/Saturation Adjustment layer and clip it to the previous Curves layer. Drag the Saturation slider to -50. We do these steps because this is supposed to be a reflection so it should be less colored and light than the original.
Add yet another clipped Curves Adjustment layer and drag the curve downwards to darken. Fill the layer mask with black and paint with a white soft brush at the edges of the apple to darken. Your image should look like the one in the image below.
Repeat steps 21 to 25 for the left reflection.
It looks pretty good now so let's start adding the details. Notice that a city is reflected in the metallic apple but the apples are placed in a white background. That's not too good. Let's add some city background. Open file "City" and press Ctrl + A to select all and Ctrl + C to copy. Paste it in our document (Ctrl +V).
Press Ctrl + T to Free Transform and make this layer bigger by holding Shift and dragging from the corners so only the left bottom half of the image will be visible.