In these 2 images I used color to give the feeling of the 2 words. The joy side of the image is full of color and the sorrow side is down in black and white. In the second image you can see the in the middle of the image it overlaps. Because I believe joy and sorrow go hand and hand. I enhanced the color of the second image with the curve tool and I used the liquefy tool all over the first image and on the dots on the sorrow sad in the second image. Then I used the tool on the first image to give it a look of steel.

joy 
1.
the emotion of great delight or happiness caused by something exceptionally good or satisfying; keen pleasure; elation: She felt the joy of seeing her son's success.
2.
a source or cause of keen pleasure or delight; something or someone greatly valued or appreciated: Her prose style is a pure joy.
3.
the expression or display of glad feeling; festive.

sor⋅row 

1.
distress caused by loss, affliction, disappointment, etc.; grief, sadness, or regret.
2.
a cause or occasion of grief or regret, as an affliction, a misfortune, or trouble: His first sorrow was the bank failure.
3.
the expression of grief, sadness, disappointment, or the like: muffled sorrow.
–verb (used without object)
4.
to feel sorrow; grieve.