Aside from being cozy and usually thought of in correlation (drinking a cuppa while reading a book) I think both the mug and the book bring love and joy. Usually a book you are reading is a book you are curious about, and a cup of tea is in a mug you think is lovely. Both the mug and the book hold stories inside them, the book’s is between the pages and the mug’s is a combination of where you got it from, why it’s important to you, the pattern and what it’s made from. (I think I might be getting too sentimental about mugs)
Santomental mates! I made a cup of tea because of this post hahaha