Meaning
Wide, staring eyes and bright red cheeks: a face caught completely off guard. It can mean embarrassment, shock, disbelief or being flustered, the feeling of “did that really just happen?”
Typical moments include an awkward slip, a bold compliment or an outrageous piece of news: “Wait, you sent that voice message to the whole class group 😳” It can also mean “wow” when something is unexpectedly impressive. Since it covers both shame and surprise, the words around it decide which one you mean.