Our overall impression of a person, company, brand or product influences our feelings and thoughts about their entire character or properties. In other words, the tendency for a person or object's positive or negative traits to "spill over" from one area/dimension to another one.
In a study, people perceived as being more attractive were more likely to be perceived as trustworthy and friendly. What this suggests is that perceptions of attractiveness may influence a variety of other traits.
How to spot - Are consumers making unfounded conclusions about a brands attributes - particularly if they find the brand particularly attractive or unattractive (negative halo effect).