What is an example of metaphor in the novel, Yes No Maybe So?

Cake is a symbol of how relationships are messy - literally and metaphorically - but how the right person can make you braver, and happy whether it lasts forever or not. Maya’s mother tells her about how she had stage fright at her wedding with her father, and her father took cake and smashed it in her face. This relieved her stress and made her laugh, and they chose that wedding photo over all of them to display in the house. Later, Jamie takes Maya to Intermezzo Cafe where they split chocolate cake. Jamie tells Maya this is where his parents had their first date. Later the waitress tells them they are the cutest couple - which makes them both embarrassed as neither is sure they are actually dating each other, or if the other even likes them romantically. At Sophie’s bat mitzvah, knowing Jamie is nervous, Maya takes Jamie into a coatroom and smears chocolate cake on his inner wrist in the shape of a heart, in order to calm him down in the same way her father did to her mother at their wedding.