Rear brake caliper hanger/bracket question

[SpongeBob]

Hi all,

Would you know by any chance the exact purpose of the square-shape profile of the rear brake caliper hanger/bracket, I mean the surface on it's side that lies against the swingarm, considering that GSXR's and Hayabusa's bracket's shoulder profile is much smaller, and also that the spacer on the other side of the wheel doesn't show such a square-shaped shoulder (so it's not necessarily a question of contact surface)?

[Eric GSX1400K3]

Just aesthetics I think, it matches the square washer on the other side

[Hooli]

Looking at the contact area you see from the markings on it, I'd agree it's only for looks.