困惑した顔

A yellow face with scrunched, X-shaped eyes and a crumpled mouth, as if quivering in frustration or holding back tears. May be used to represent being overcome with various emotions, including irritation, frustration, disgust, and sadness, as if to the point of defeat.  

Microsoft and Twitter’s designs feature eyebrows, Facebook’s a purple forehead.

Vendor designs have noticeably evolved over time. Apple and Google’s designs previously included eyebrows. Earlier versions from Google also displayed a more miserable expression, and Microsoft a more confused one.

Samsung’s design previously featured X’s for eyes, a flushed nose, and vertical lines over its forehead, shorthands in manga and anime for such feelings as anger and embarrassment.