This statement carries a sweet and romantic sentiment. It conveys the idea that the person addressing someone is struggling to find the perfect word to describe them, but in the end, they believe that the word "mine" encapsulates their feelings and connection.
It suggests a possessive yet affectionate attachment, indicating that the person feels a deep sense of ownership and commitment to the person they're speaking to. "Mine" in this context implies a strong bond and a sense of belonging.
Overall, it's a charming way to express the uniqueness and exclusivity of their relationship, where the word "mine" signifies that this person is a cherished and irreplaceable part of their life.