I think it slightly resembles a mask. And seeing how its buried underneath all of the eyes, I would say it represents how madotsuki feels underneath all of her angst.
I think that because I think the eyes in the game represent paranoia or anxiety.
So maybe she's trying to "mask" her true feelings?
Tbh I clearly see a penis and two balls
it's a penis that represents rape under all her angst
mado is a penis