Why does my scar has this uneven horizontal shape? Can this be fixed? (photo)

The puckering and wrinkling of the skin will improve significantly with time. The asymmetry of the actual scar line is probably a result of some inaccurate pre-operative markings by your surgeon. Once you have healed completely (3-4 months), you can improve the positioning of the scar by removing some additional tissue from below the scar on the left side. 

your incision will change over the next several months.  It would be reasonable to revise at a later date.  

poorly thought out incision placement and bunching is node in the posted photos. Revision possible but over the internet can not tell.///

Once the incision line and skin has relaxed after six months from surgery, the higher scar line can be lower by removing some additional skin below it.