Masks in TGCF

Hi All,
I wonder why Jun Wu chose the half crying, half laughing mask for Xie Lian since he wanted to turn him into White No Face (His past self).
Is it related to" Body in abyss, heart in paradise" phrase because it emphasizes the contrast? Does it show that Jun Wu goes to extremes and never in between, or is it like a Yin Yang balance?