The halo effect is a theory that posits that various positive traits also increase the (false) impression of other positive traits. E.g. people who are more aesthetically attractive are subconsciously assumed to have a much more virtuous personality and to be much more healthy and to have much higher IQ, none of which is true. The halo effect also goes into the implications of such a subconscious stance, such as the subsequent greater career prospects that better looking people get. The opposite of the halo effect is the horn or failo effect. Halo effect allows attractive people to get away with violating any and all social norms, also any negative and or androgynous qualities they may have are over looked, as in literally not noticed. No one questions Stacy's sexuality despite her strong jawline, and determined attitude, nor Chad's sexuality despite having huge duck lips, and dancing around in a multi colored jumpsuit, but if an incel guy were to wear the exact same outfit, the incel guy would be labeled as gay immediately. Also if a regular girl was to act like Stacy, she would be immediately bullied as well.
The better one knows someone, the less halo effect plays a role. For example, after a while teachers can guess their student's IQs as accurately as doing an IQ test.