The porn video tag "natural-trans" refers to a specific category within the adult entertainment industry. In this case, "natural" suggests that the transgender performer in the scene has not undergone any significant gender affirming surgeries and presents more like their natal gender than their affirmed gender. "Trans" is short for transsexual or transgender, indicating that the performer is transitioning or has already transitioned from one gender to another.
In a natural-trans scene, the focus may be on the performer's natural body, including their genitals and other physical features associated with their natal gender. This can be an appealing aspect for viewers who are interested in the process of transition or appreciate the differences in gender expression and presentation.