1. Bone structure: The shape of nostril is mainly determined by the bone in the middle of nasal cavity, namely nasal septum. If the angle or shape of the nasal septum changes, it may cause the nostrils to take on a lovely shape.
2. Genetic factors: human genes also affect the shape of nostrils. If one nostril in the family has the shape of love, it is likely to be passed on to future generations.
3. Expressions and actions: Sometimes, people express their emotions through specific expressions and actions, such as wanting to express feelings of love and happiness. These expressions and actions may make the nostrils take on the shape of love.
However, these are only possible reasons. Due to individual differences and environmental factors, the specific reasons may vary from person to person.