People usually come to a conclusion about the personality of a person on their first meeting, they also decide whether they like them. I personally believe it is a bad thing, and coming to a conclusion based only on physical appearance of a person is morally wrong. Also, I think talking and exchanging ideas must be the basis of judgement.
First and foremost, physical appearance of a person does not reveal their inner character. Besides this, whether someone likes or dislikes a person does not usually concern their external features. For instance, a person working in a glass factory has to deal with immense heat, meeting them for the first time during their work will depict that the individual is very rude and violent, since the amount of heat has affected that person. The same worker if met for the first time during his vacation would be a decent and generous gentleman.
Another thing to be considered here is, only one meeting would not expose the real traits of an individual, since everyone would try to be calm and compose when they meet someone for the first time. Therefore, multiple meetings, talks and exchange of ideas would unearth the true personalities. For example, my friend had found his date to be very respectful and interesting but after few dates she found that he was a criminal and has a case booked for harassing her ex-girlfriend.
In conclusion, first meetings are usually considered to be the best time to know the inner qualities of a person and a take a decision about likability. I think it is a bad thing, because phenotypic properties does not reveal the inner characters of someone and multiple meetings along with exchange of ideas would expose their inner qualities.