Maybe for some reason, some aspect of your physical constitution connects with subconscious content in the person's mind. In some way you look like someone else in the individual's life who has behaved (in thought or deed) in a way that is repellent to the morality of the individual. Hence: Judgment.
In cases like this, the projection of the content of the unconcious mind often shows repressed tendencies in the individual. They are too unwilling to recognize these "abhorrent" qualities in themselves, so they project them onto a more palatable object (you).