How do you feel when you see hot girls or boys who are attractive? Do you want to go out with them? You might think like that at first, but as you spend time with her/him, you might change your mind. Human beings are stereotypical animals, who unconsciously judge people by their looking. The first impression, therefore, is essential to give good feeling toward others, when the amount and type of information provided about a target is limited. However, the first impression does not last long enough to show people that the physically attractive people are not that attractive. I consider myself physically attractive (I am half kidding), but when girls spend time with me, they easily get bored.
According to the research by Heilman in 1983, a perceiver makes inferences about attribute, and characteristics of an individual based upon stereotypes, such as sex and attractiveness. Then he/she evaluates the individual on the degree to which these attributes match the perceived requirements of a job. However, people place little or no reliance on stereotypes when information about the target is clearly and unambiguously judgment relevant. For example, a meta-analysis by Tosi and Einbender in 1985 showed that sex bias was greatly reduced when more-job relevant information was provided than less-job relevant information was provided. See more information here
My first impression may be an advantage when interviewing a job (this is just my thought), but I should show my relevant qualities to interviewers.