After looking at your post I went to look at others and noticed that all the ones I am seeing even in different years, have that same doubling effect on the face. Nice double chin and yet he does not look overweight. lol Are there any out there that don't have the same thing going on or this just normal for this series???
I imagine that it's because of the incuse design -- you're seeing a reflection of the field's edge in the chin's curve. I don't think it's an actual feature.