What can be done about facial asymmetry / uneven masseter? (photo)

Hello,before I explain,my goal is not perfect symmetry but to make asymmetry less noticeable.I’ve noticed significant asymmetry between the left and right sides of my face in photos.I’ve had Botox for a larger masseter on the left side,as the size difference was noticeable during evaluation.What could cause this,and what other options can help?Photos with a green dot aren’t selfies;those with a red dot are.Thank you!