This is something I did with my sigi and I rembember someone asking how to do it.
Step 1:
Take the line/curve tool and make the space in which the difference will be.

P.S. Make sure the line touches the top.
Step 2:
Now add anycolor to one side. Same with the other only different color.
Part 3:
Now go to Effcets-Blurr-zoom blurr and choose how much blurr you want.
Part 4:
Now go to Effects-photo-glow and choose how much glow you want.
Part 5:
Enjoy your photo!
It looks different cuz I added less glow and more radious.
I called it higher and lower cuz it looks like one platform is higher than the other.
You could go a lot farther than this. Mine looks boring and dull.