Being "obsessed" with tall people in itself doesn't necessarily indicate Obsessive-Compulsive Disorder (OCD). OCD is a mental health disorder characterized by intrusive and unwanted thoughts (obsessions) that lead to repetitive behaviors (compulsions) in an attempt to alleviate the distress caused by those thoughts.
It's important to differentiate between having a preference or being interested in tall people and experiencing true obsessions related to OCD. If someone has a preference for tall individuals or finds them attractive, it is a personal preference or a matter of individual taste and not necessarily linked to OCD.
On the other hand, if a person is experiencing intrusive, distressing, and unwanted thoughts about tall people that they feel compelled to act on or engage in repetitive behaviors related to these thoughts (such as excessively researching tall people, constantly measuring heights, etc.), and these thoughts and behaviors significantly interfere with their daily life and cause significant distress, it could potentially be related to OCD or another obsessive-compulsive spectrum disorder.
It's important to remember that a diagnosis of OCD or any other mental health disorder should only be made by a qualified healthcare professional after a thorough evaluation of the individual's symptoms and history. If someone is concerned about their thoughts, behaviors, or mental health in general, it is recommended to seek the guidance of a mental health professional. They can provide a proper assessment and recommend appropriate treatment if necessary.