Like someone else mentioned, it might be the other girls are shapelier than Kson (the ones on the corners are definitely sticc-chic) but focusing only on the JAV actress and the gravure model with Kson between them, you can see she is slightly, barely noticeably chubbier than on the fishing video.
Looking at it now, it seems most of the weight went to her breasts and butt.
Which is in no way a bad thing! View attachment 22329
Yes, I am simping like a motherfucker. Yes, in Kson's case it's not a bit. I don't care.