Unicode 1F595, more commonly known as the middle finger emoji.
Have you ever heard someone says something that sounded completely outrageous, and you turned around to see a smile on their face and heaved a sigh of relief?
Humans rely on a wide range of signals to communicate with each other, and most of these are non-verbal: What we say is modified by pitch and loudness of voice, body language, hand gestures, and facial expression.
Written communication has none of those signals, so letter writing was very formal and structured to avoid miscommunication:
"Dear so and so...