A simile is describing the relationship with “like or as”, but it’s not literal. I dint k,now the book, but it really depends on their relationship. For instance, “my dog and I were like peas and carrots, we belong with each other.” A metaphorical phrase would be using figurative language, but without using “like or as”. For example, “my dog and I were glued to each other, we were inseparable.”
