on Just Publishing Advice:
The easiest way to understand tone in writing is to think about emoticons.
When you send messages to friends, you often add an emoji to say that you are happy, sad, confused, or being sarcastic.
But you can’t add icons when you are writing blog posts, articles, or books.
Tone is a writing skill that you can develop to improve your communication, clarity, and storytelling in both content writing and books.