自身の胸をふくよかに見せたい女性の気持ちを叶える胸のイリュージョンTシャツを着る様子です。
目の錯覚をデザインに取り入れたTシャツで、販売もされているようです。
Translated from Japanese by Google
It looks like she is wearing a breast illusion T-shirt that fulfills the feelings of a woman who wants to show her breasts plumply.
It seems that T-shirts that incorporate the optical illusion into their designs are also on sale.