I duplicated the source image and flipped it. Then, I began to remove gumball parts with a mask and added gumball parts with a combination of brushes, stamp, burn, dodge, and blur.
step 2 of 5
After I felt confident with the seam, I changed the color of the largest gumball to reduce the appearance of mirroring using a path and hue/saturation.
step 3 of 5
Then I used the pen tool to mask out the background and brought in two backgrounds. The one on top is a multiply layer. I also started to add clouds with a combination of cloud brushes and a large soft brush.
step 4 of 5
I continued to work with the clouds and started to use the blur and smudge tool for the edges of the "mountain" to make it look more like a single pile and burned the edges to make the mountain more realistic and ominous. I also added a touch of purple with a light soft brush towards the back to mimic nature and the bluish appearance of mountains in the distance.
step 5 of 5
Finally, I erased a bit of the mountain where I wanted to draw a sun rising in the background with several soft brushes. I also removed some of the unnecessary reflections from the gumballs to help the new light source make sense.