It's the roof on the top.
Also, I'm using the same model for each pose so having one pose look like having larger limbs is impossible,
Jalis: Freelancer, you're a duck | Sachi: Freelancer, you're a duck | Reanimator: Freelancer, you're a duck
satiknee: Freelancer, you're a duck | Wiggi: Freelancer, you're a duck | Tarlan: Freelancer, you're a duck